Sara Dybris Mcquaid

Sarah Gensburger
email: sarah.gensburger@cnrs.fr

Sara Dybris Mcquaid

Administrations of memory: Transcending the nation and bringing back the state in memory studies

Keywords: Administrations, Memory, Policy, Transnational, Northern Ireland, France

This introduction to the special issue starts from the point that studying the politics of memory should also involve studying the governance and policies of memory: its administrations. The increasing importance of transnational and local scales in memory studies seems to have made the nation a less relevant starting point from which to conceptualize memory. Yet, states progressively attempt to administer memory. This suggests that we should focus at once on transcending methodological nationalism and bringing back the state in the study of the politics of memory. This involves thinking about administrations of memory both in terms of the processes of dispensing or aiding memory and as the state bodies that are authorized and expected to manage memory. As such, this introductory chapter is structured around two issues: a) the interactions between transnational, national and local scales in policy trajectories, practices and discourses on Administrations of memory: Transcending the nation and bringing back the state in memory studies 1

memory and b) The role of governance and administration in understanding memory as a category of public intervention. Both sets present a thumbnail case to illustrate the issues at stake and taken together they develop our on-going reflexions on memory as a contemporary conduit for practicing politics and setting up political institutions. The ambition is for memory studies to gain a firmer understanding of the governmental and technocratic coproduction of political languages for memory as they are themselves shaped in the policymaking process by (trans)national institutional practices and bureaucratic conduits. In turn, political science approaches on the whole may gain from a firmer appreciation and conceptualisation of the structures and carriers of collective memory in and across particular political cultures, which may also lead to more reflexive policy instrumentation and programming in contemporary societies trying to deal in and with the past.

Introduction

Since the beginning of the 1990s, governments across the world have increasingly been implementing public policies to promote remembrance with a view to govern society [START_REF] Gensburger | A quoi servent les politiques de mémoire? Paris[END_REF]. Political science and memory studies have both engaged with this but from different perspectives. While there is a significant body of work in political science which deals with the 'politics of memory', particularly in studies of nationalism, much of this work neglects to adequately theorise what kind of a phenomenon or process the evoking of memory is considered to be. At the same time, memory studies scholars, who have no lack of theoretical sophistication on the conceptualisation of different formations of collective memory, tend not to engage with memory politics and commemorative practices beyond competing discourses and actors. That is, they often leave out considerations of the governmental regimes, political cultures, institutional structures, bureaucratic practices and policy processes through which memories and memorial practices are filtered.

The increasing importance of transnational and local scales in memory studies seems to have made the nation a less relevant starting point from which to conceptualize memory.

Yet, states progressively attempt to administer memory. Taken together, this suggests that we should not only look beyond the nation, but also look closer at the state in our endeavours to understand the politics of memory. Here, we suggest that the study of memory should apply perspectives from public policy analysis to investigate the nature of contemporary states in 1 Corresponding Author, School of Communication and Culture, Aarhus University. Email : engsdm@cc.au.dk 2 CNRS French National Center for Scientific Research. Institut Science Sociales du Politique. Email : sarah.gensburger@cnrs.fr disjunction with the nation, as well as use memory studies to investigate the 'policy state' which characterizes our time [START_REF] Orren | The policy state. The American predicament[END_REF], and its possible limits. So, we start from the point that studying the politics of memory should also involve studying the governance and policies of memory: its administrations. Accordingly, our special issue strives to develop cross-fertilising contact points between political studies and memory studies in their diversity. This involves expanding the focus in memory studies on available languages and how they give shape to policy to include how these political languages are themselves shaped in the policymaking process by (trans)national institutional practices and bureaucratic conduits in order to gain a firmer understanding of the governmental and technocratic shaping of memory. In turn, political science approaches may gain a firmer appreciation and conceptualisation of the structures and carriers of collective memory in and across particular political cultures, which may lead to more reflexive policy instrumentation and programming in contemporary societies trying to deal in and with the past, also in symbolic and narrative terms.

While our special issue starts from a specific cross-fertilization between memory studies and political science, we have included researchers from a variety of different disciplines and perspectives: Political Science; International Relations; Sociology; Cultural Anthropology; Philosophy; Contemporary History. The ambition is not just to be 'interdisciplinary' in the sense of bringing these together within a shared framework, but moreover to develop transdisciplinarity in a generative synthesis of disciplinary approaches, which may capture what is between, across and beyond each discipline [START_REF] Nicolescu | Transdisciplinarity -theory and practice[END_REF].

Therefore, the kind of questions we ask, the material and methodologies we use, and the theories we propose in relation to memory and politics are not just about developing contact points between political studies and memory studies, but about paving the way for new kinds of inquiries into the governance of memory more widely.

In this introductory chapter we first set out our own reflections on how to begin this dialogue between memory studies and political science, focusing at once on the dual importance of transcending methodological nationalism and bringing back the state in the study of the politics of memory. This involves thinking about administrations of memory both in terms of the processes of dispensing or aiding memory and as the state bodies that are authorized to manage memory. As such, the initial reflections are structured around two issues: a) the interactions between transnational, national and local scales in policy trajectories, practices and discourses on memory and b) The role of governance and administration in understanding memory as a category of public intervention. Both sets present a thumbnail case to illustrate the issues at stake and taken together they develop our on-going reflexions on memory as a contemporary conduit for practicing politics and setting up political institutions. In this introductory article the cases are drawn first from Northern Ireland and then from France, enabling us to discuss our perspectives in relation to very different types of state trajectory and structures. That is, respectively, what is most often typified as a weak and a strong state [START_REF] Birnbaum | State, centre and bureaucracy[END_REF][START_REF] Novak | The myth of the "weak" American state[END_REF], or a union or a unitary state [START_REF] Bogdanor | Devolution in the United Kingdom[END_REF].

After these theoretical and empirical reflections, we introduce the six papers that together constitute the issue. Coming from different disciplines and themselves drawing on empirical case studies, each article develops new views on key concepts such as transnationalism, agonism, political culture, policy transfers, and bureaucracy. In various ways, these six articles thus cross scales and methodologies to rethink the place of nation and state in the governance and policies of memory.

Administrations of memory beyond the unitary nation and state

In this section, we draw on conceptualizations of transnationalism in political science and memory studies to argue that policies of memory must be considered in a wider framework than that of the nation-state. Drawing on a case from Northern Ireland, in which state institutions are not tied to a single national identity, we argue that transnational and local scales play key roles in shaping policies of memory, and that studies of the administration of memory thus must attend to multiple scales and in particular to their interactions in specific policy contexts.

Transnationalism between political science and memory studies

Transnationalism in political science was popularized by Nye and Keohane in their 1971 special issue 'Transnational Relations and World Politics' which sought to move beyond 'state-centric approaches' in studies of international politics. What we might heed from their early conceptualization of transnationalism is first to appreciate that 'intersocietal interactions' (e.g. transnational social movements), are more than mere 'environments' for interstate politics (p. 725) and second, to challenge the assumption that the state is a unitary actor (p. 731). Studying how 'intersocietal interactions' affect interstate memory politics, enables us to appreciate how choices open to statesmen and -women are altered in a synchronic policy process, emerging at once from the bottom-up and the top-down and circulated through particular institutions and practices. This multidirectional dynamic also changes the corresponding costs of political action and choices. If we move on to challenge the state as a unitary actor, we need to conceptualise transnationalism in a way that captures intra-state politics as well as interstate and intersocietal interactions. In other words, we need to stay alert to the political struggles between state departments and levels of national, regional and local government, which are also part of the co-production of transnational policies and practices. That is, in the dynamics between these different environments, different political and policy possibilities may exist for conducting foreign and memory policy. We will return to this, specifically, in the cases below and in a number of the articles to follow in the issue at large. The disciplines of International Politics and International Relations obviously study transnational transfers and dynamics of policy agendas but often stay at the macro level (world polity/system) and rarely include how those processes are constituted by, and constitutive of collective memory concerns. Borrowing from Tarrow, we suggest that the study of transnational memory politics should be examining the links between domestic and transnational actors and states and international institutions, not least by examining the gaps between the reach of states and international institutions [START_REF] Tarrow | Transnational politics: Contentions and institutions in international politics[END_REF]. Such gaps may appear in dissimilar ways as 'differences in domestic structures determine the variation in the policy impact of transnational actors' (Risse-Kappen 1995, p. 25, quoted in Tarrow). If we want to study which systems, societies and substances are more open to transnational interaction, particularly in relation to forms of memory politics, we propose that we more fully incorporate the body of political science literature which explores concepts of political culture. As such, we would be studying the reach, gaps and legitimacy of local, national and supranational institutions and actors in transnational memory policy, also for comparative purposes in which we could explore the flexibility and permeability of political cultures, not least in terms of the different memory modes variably engaged, in policy processes and practices. We will again return more firmly to this below.

Compared to political science, the concept of transnationalism is a much more recent arrival in memory studies, where it has only been firmly on the mainstream radar in the past five-ten years (see for example Assman 2014; De Cesari & Rigney 2014). On the one hand, the reigning primacy of national frames for understanding collective memory and identity is not surprising given the importance attached to national institutions in constructing top-down national narratives since the nineteenth century. On the other hand, one of the core subjects of memory studies, remembrance of the Holocaust, is obviously cosmopolitan and multidirectional, and has been studied as such (see for example Levy & Sznaider 2002;[START_REF] Rothberg | Multidirectional memory. Remembering the holocaust in the age of decolonization[END_REF]). The introduction of transnationalism into memory studies, then, is not a completely new perspective, but rather a new conceptualisation that is gaining increasing purchase alongside established terms like 'post-colonial' and 'multicultural' in the ongoing move beyond nationalist methodologies (Assman 2014; Gensburger 2016a).

Conceiving of memory and commemoration in transnational terms, speaks very directly to the decentralization of memory enabled through new technologies and patterns of migrationand not least in the interaction between new technologies and migration. De Cesari and Rigney posit that conceptualising transnationalism in memory studies means rethinking what 'scales' (interactions between local, national and supranational), 'circulation' (communication and technology) and 'articulation' (mediation and narrativization) mean and how they work separately and together (2014). Encapsulating the term, they suggest that the concept of transnational is well suited to open new possibilities 'for examining the interplay and tensions between culture and institutions' particularly, in being able to capture analytically the continued importance of imaginary and legal borders in memory studies. In this, the nation doesn't disappear, but becomes one among a range of phenomena to be studied, rather than the framework for study itself (cf. Vertovec 2009; Iriye 2012). In their work on transnationalism, Rigney and de Cesari insist on the urgency of developing new theoretical frameworks and new methodologies for studying collective remembrance beyond the nation state. They also argue that the term transnational more easily allows for a dialogue 'between those approaching the field from the humanities and those approaching it from the social sciences ' (2014, p.4). However, they don't explicitly think about political science as a social science and the state remains an elusive actor at all scales. This means that transnationalism in memory studies is being explored mostly as 'social morphology', 'type of consciousness', 'mode of cultural reproduction' and '(re)construction of place and locality', and less as a 'site of political engagement' and as an 'avenue of capital' (to borrow Steven Vertovec's typology of transnationalism ( 2009)). To engage transnational memory as a site of political engagement and an avenue of capital would mean studying forms of transnational governance and globalizing bureaucrats more explicitly when exploring public policies and politics of memory. We suggest that some of the 'new' tools needed in memory studies, already exist in mainstream political science, which however so far has paid very little attention to complexes of memory. Indeed, confronted with the contemporary transformations of the state, some political scientists have formalized ways of conceptualizing society beyond the nation but in relation to state dynamics and structures [START_REF] King | Reconfiguring European states in crisis[END_REF], which allows us at once to think about transcending the nation and bringing back the state.

Political culture and policy analysis

One such tool is the concept of political culture, which has mainly been developed and employed in political science and history [START_REF] Formisano | The concept of political culture[END_REF]. However, for the purposes of extending contact points between political studies and memory studies we want to suggest that the concept is a capable carrier in moving forward. In very brief terms, political culture at the cognitive level refers to the rules of the game, the institutions, the actors, the laws and the stable repertories of salient themes, values and attitudes (e.g. trust in political institutions, and perceived ability to act in political roles) in a polity. At the normative level, it refers to the 'socially constructed and tenuously shared meanings which endow or challenge legitimacy in the political institutions, offices, and procedures of a polity' (Aronoff 2002, p. 11640).

Political culture approaches thus encompass the study of both the politics of culture and the culture of politics.

It has been demonstrated elsewhere how studies of collective memory and political culture, share an ontological split between individual and collective conceptualisations [START_REF] Mcquaid | Notes on studying public policies of memory: The parades commission in Northern Ireland and the institutionalization of memory practices[END_REF] which make mutual transfers into existing research paradigms easier.

Furthermore studying collective memory and political culture share certain challenges, such as normative bias in terms of the status quo (i.e. nationalist methodologies); excessive focus on expressive power dynamics to the exclusion of material practices; and problematic reification of culture (not recognising differences between dominant-and sub-cultures).

Framing the political and its boundaries also as a cultural question would be one significant outcome of bringing the concerns of memory studies and political studies closer together.

Here we are specifically interested in the kind of common research agendas that can be pursued when tracing collective memory as a figure through political culture: That is, how do political institutions and bureaucratic practices shape and change patterns of democratic participation in formations and manifestations of memory? And conversely, how do commemorative practices impact political integration and the democratic participation of citizens in policymaking?

Often the politics of memory is studied without recourse to corresponding policy. That is, as public debates that do not refer to action, nor announce action, but are actions in themselves (König 2003, cited in Meyer 2010, p.178). In memory studies, while the interplay and interpellations between international organisations, institutions and instruments like the EU, the International Court of Justice, UNESCO, national governments, social movements and local spheres are (increasingly) included in analysing the configuration and distribution of memory in discourse coalitions, these interactions and institutions are not often studied as policy processes beyond agenda-setting and representation. As such, policy often remains in the abstract, and actual decision-making, (re)formation, delivery, implementation, evaluation and feedback remains in a black box. Here we want to know: how are de facto memory policies shaped within society, state and transnational organizations, and by whom? With which other networks and sectors of public policies do they interact? Which procedures and practices do they percolate through?

Storytelling projects in Northern Ireland: Transnational memory politics without policy?

In the following, we will briefly present a case of a complex co-production of transnational memory, in which political cultures and stages of policy processes serve as analytical entry points. In a broad sense, the case is about how to deal with the past in the ongoing Northern Ireland peace process.

In 1998, after 30 years of violent conflict, a peace agreement was signed in Northern Ireland. While it was a comprehensive agreement in many respects, it did not set out an overarching policy framework for dealing with the legacy of the conflict. In 2018, twenty years after the agreement was reached, there is still no unified political or legal approach in place to address the particular past of the so called 'Troubles' in no small part because of the deadlocked nature of Northern Irish powersharing politics. Instead, this space has been filled by a variety of international-, state-, and society actors, working separately and together in pluralistic, contradictory, and cumulative ways [START_REF] Mcevoy | Dealing with the past? An overview of legal and political approaches relating to the conflict in and about Northern Ireland[END_REF]McQuaid forthcoming 2018).

As one track in this process, this case is more specifically about how 'storytelling projects' 3 in which individuals remember life during conflict, have become important conduits in undertaking the particular task of dealing with the past in peacebuilding. We ask what 3 The Northern Irish NGO Healing Through Remembering defines storytelling as 'A project or process which allows reflection, expression, listening, and possible collection of personal, communal and institutional stories related to the conflict in and over Northern Ireland ' (2002).

happens to administrations of memory, when political institutions themselves are so to speak 'in administration,' i.e. contested, unable or unwilling to perform the role they normally would perform, when it comes to conceiving of and implementing policies. This allows a clearer view of the ways in which transnational and local actors can come together as a policy community and how collective formations and manifestations of memories at once shape and are shaped by formal political attempts at governing the past.

In this thumbnail sketch of the case we want to address the three contact points set out above by: 1) discussing the national political culture in which it is constituted and operates, 2) tracing the transnational webs of peacebuilding norms, funding regimes and best practices (themselves forms of political cultures), through 3) stages of policy analysis. The sketch is obviously not exhaustive, but bringing these points together allows us to reflect on some key questions about blocks and flows in transnational trajectories of memory policy and -making, in relation to specific political cultures and patterns of democratic participation.

From memory narratives to political culture as analytical tool

The political culture in Northern Ireland has been conceived as deeply divided between overlapping ethno-political communities of Protestants/unionists and Catholics/nationalists.

The peace agreement of 1998, gave institutional credence to such interpretations, by making powersharing, or consociationalism [START_REF] Lijphart | Democracy in plural societies: A comparative exploration[END_REF][START_REF] Mcgarry | The Northern Ireland conflict: Consociational engagements[END_REF], between these two communities a main pillar of the political solution to the conflict. Powersharing has since been borne out in what was already a largely ethnic dual party system (Mitchell 1997), in which there is little transfer of votes between the main political community blocs, but fierce competition within them. Furthermore, while powersharing has been agreed as an acceptable form of governance, the future constitutional status of Northern Ireland remains potentially contested. The peace agreement enshrines the right to pursue mutually exclusive constitutional aspirations by democratic means (that is, Northern Ireland continuing to be a part of the United Kingdom, or become a part of a future united Ireland), and this complicates a 'fusion of horizons' in which the conflictual past could be transformed and projected into a shared future. Historical touchstones, myths of origins and important markers of identity thus, to some extent, continue to be produced in exclusive parallelism, where politicians use the past to mobilize political support in the present to safeguard the future. While the political system, by and large is deadlocked on issues to do with the past (as well as polarized on a wide range of other issues), there is also a strong tradition for an active community sector and a critical citizenry in Northern Ireland. Between 1972 and[START_REF] Polletta | Legacies and liabilities of an insurgent past: Remembering Martin Luther King, Jr., on the house and senate floor[END_REF] Northern Ireland was governed by direct rule from Westminster, creating a political institutional vacuum, which afforded important democratic and governance roles to civil society in developing and implementing policy. Such political roles have continued beyond the peace agreement, in the absence of party political ability to move agendas forward. Importantly, peacebuilding, both at this civic level and at the level of political negotiations, has been increasingly transnational since the mid-1980s. At this point in the peace process, in lieu of effective policies on how to deal with the past, best practices from other conflicts and funding from international organisations and institutions, especially the EU, have acted with local agencies to fill policy gaps. It is as part of this transnational policy community4 that we locate the expanding trend of storytelling projects as conduits for breaching and bridging pasts.

Storytelling projects as multi-scalar policy processes

Like the stages in conflict and peacebuilding (see for example Darby 2001; Ball 1996), policy analysis offers a sequence of stages or incision points that may be usefully engaged to structure analysis. Among these are agenda-setting, implementation, evaluation and feedback.

However, these processes rarely develop in linear fashion, nor are the stages neatly separable or exclusively at play at any one time (Weible & Sabatier 2017). Since formal policy has yet to be implemented on dealing with the past in Northern Ireland, I will use the policy stages here as entry points for the disentanglement of indirect decision making by pre-policy practices, which are at once shaped by the absence of policy and give shape to future policy.

In this, it also becomes clearer how administrations of memory happen at multiple levels and in complex temporalities.

To a certain extent, the agenda-setting for dealing with the past is set or at least circumscribed by the parameters and dynamics of the peace agreement itself, as set out above.

On the one hand the political deadlock determines what pasts can be dealt with and on what terms. On the other, this also means that more agile and less antagonistic agenda-setting can take place. One such approach has been the blossoming of local storytelling projects. The Northern Ireland NGO 'Healing Through Remembering' (HTR) has been particularly important in formalizing this agenda and working out broader alternatives to the lack of policy in the field. 5 In 2001, HTR undertook a public consultation on the question: How should people remember the events connected with the conflict in and about Northern Ireland and in so doing, individually and collectively contribute to the healing of the wounds of society?

Identifying some common ground, one of the most widely endorsed approaches in the consultation was one of a collective storytelling and archiving process, which was argued to offer the dual benefits of working as a vehicle for catharsis for individuals, as well as function to establish a record of individual stories. This record, would in turn enable society to examine 'the wealth of meanings and learning connected to the conflict' [START_REF] Mcclelland | Healing through remembering: The report of the healing through remembering project[END_REF].

At the same time, preserving a myriad of narratives would ensure that dominant narratives emerging over time could be continuously challenged. As such, the agenda is at once about 'micro' and 'macro' memory in an ongoing societal and political transition, but also one that specifically welds memory to individual and collective healing and makes reconciliation the policy objective. Importantly, the establishment of HTR had its roots in a 1999 visit to Northern Ireland from the Deputy Chair of the South African Truth and Reconciliation Commission, showcasing how peacebuilding practices and policy communities travel and mutually legitimize, constitute and reinforce each other. The foundation of HTR is thus at once local and transnational while being framed by a particular national political culture.

If the agenda was dealing with the past through storytelling projects, then the Sometimes bureaucracy is seen as an antidote to the politicization of contentious issues, however, technocracies are of course a major factor in the shaping of discourses, understanding expectations and practices, not least in peacebuilding (MacGinty 2013). This can be seen in the examples above in terms of incentive structures (funding frameworks) and qualification and standardization of practices (defining reconciliation) and is of course also borne out through the evaluating procedures tied to funding. Individual storytelling projects which received money from Peace III had to define indicators, and monitoring tools to gauge and report results and impacts on peace and conflict. Such terms of reference do not singularly determine processes and outcomes, but they form a critical part of the environment in which interactions (storytelling) take place and how these stories are distributed subsequently (i.e. for measurable impact). Accessing individual stories through online archival platforms such as 'Accounts of the Conflict' 6 gives the reader, listener, or viewer little sense of the co-production at play in the making of memories. What may seem as a straightforward 'bottom-up', individual and local practice of remembering and dealing with the past is in fact part of a transnational peacebuilding effort in which bureaucratic practices and discourses and a national policy vacuum circumscribe and imprint the kinds of stories that can be told, shared, stored and accessed.

The firm focus on 'reconciling communities ' and 'build[ing] positive relations at the local level' in the PEACE III programme, stipulates a significant boundary to be negotiated in terms of what should be remembered and the correct mode of remembering for individuals and communities in Northern Ireland. At the same time, because of the absence of settled legal policy frameworks or 'time frames' of the past, there are limits to what can be publicly shared as people may be worried that stories will later become testimonies, literally held up in court, as happened in one high profile case. 7 Factoring in technocratic interventions also means being alert to how emerging hegemony in peacebuilding practices, where tools to describe and transform conflicts through storytelling and oral history are increasingly homogenized, apply in specific contexts. We 6 Online since November 2014 The 'Accounts of the Conflict' is a digital archive of personal accounts of the conflict, based in Ulster University and designed to provide for the long-term storage of stories related to 'the Troubles' in, and about, Northern Ireland. Accounts of the Conflict is funded from the European Union's PEACE lll program, managed by the Special EU Programs Body. The archive contains collections of personal accounts, the vast majority of which have been collected by a wide range of community-based organisations and projects across Northern Ireland and beyond. The Web site will also have a facility for future story-telling projects to deposit digital versions with the Accounts of the Conflict archive. (Accounts of the Conflict, web). 7 The Belfast Project at Boston College had collected life stories from the rank and file of paramilitary organisations like the IRA and the UVF from 2001 -2006 for a future establishment of a historical record, but these have been subpoenaed by law enforcements agencies in Northern Ireland since 2011 to be used in current and potential trials (McMurtrie's 2014). may say that while Northern Ireland is clearly part of establishing a transnational paradigm on how to remember the past in constructive ways -it is not simply subjected to it. Local knowledge and expertise domesticate and give shape to the specific implementation of EU funding policies on the ground, and also feeds back into revising EU parameters for reconciliation. Indeed, in the context of Brexit, the case of Northern Ireland is significantly reassembling ideas about the EU as a peace building project.

The feedback from the first and second waves of oral history and storytelling projects and practices is now informing and becoming part of the first stages of formal legacy policy in Northern Ireland. In 2014, after 11 weeks of negotiations, the political parties in Northern Ireland reached agreement on a flexible policy architecture including an independent 'Oral History Archive' alongside an 'Independent Commission for Information Retrieval' (ICIR) and a 'Historical Investigations Unit' (Stormont House Agreement 2014 (SHA)). However, navigating continuing political differences, and in response to emerging problems in existing plural processes of dealing with the past, the SHA set out to patrol the lines between different kinds of truth and justice by establishing membranes between categories of materials, levels of analysis and legal mechanisms. That is for example, stipulating differences between forensic truths (evidence) that may lead to criminal justice and narrative truths (stories) that may lead to restorative justice. Earlier policy proposals (Consultative Group on the Past 2009;

Haass/O'Sullivan 2013) included clearer conduits for bridging individual cases and macro history whereas the SHA repeatedly stipulates that these new institutions 'must not seek to rewrite history […]' (Northern Ireland Office UK SHA 2014, p. 6). This of course has consequences for the ambitions for the collected stories also constituting a reservoir for challenging dominant narratives.

The Northern Ireland Assembly has currently been suspended since January 2017 without having implemented the SHA. At this stage, Northern Ireland is returned from a state of politics without policy, back to a state of policymaking without politicians in institutions, with particular opportunities for transnational actors to maintain access to the political system.

In May 2018, the British Government opened a public consultation on whether the SHA proposals 'can effectively address Northern Ireland's past,' asking specifically for evidence given on 'How well do the proposals for the Historical Investigations Unit, the Independent Commission on Information Retrieval and the Oral History Archive meet the needs of victims and survivors?'. Veering between open public consultations followed by protracted political negotiations, often behind closed doors, is another long-standing feature of the political culture in Northern Ireland. Here administrations of memory are continuously shaped and reshaped in particular patterns of democratic participation, where the relative positioning between scales of civil society, state bureaucracy and transnational organisations in peacebuilding is a key dynamic in policy and memory formation, with largely defunct local political institutions.

What this thumbnail sketch begins to illustrate is, that administrations of memory happen at multiple levels, at once operating in separate streams, yet constantly crossing wires, intersecting and impacting each other. This of course has consequences for the memories of the past we are left with, as remembering becomes a crucial part of participating in an uncertain political transition through existing and emerging transnational infrastructures. To better capture remembering as systematic democratic participation and peacebuilding, we need to go beyond issues of shared narrative structures and symbolic spaces, to include how political processes, institutions and practices (even as failures) are part of co-producing not just storytelling projects but individual stories. When we take the proximate context of the policy environment or political culture into consideration, including the absence of political decision making, changing directions of policy and institutions designed to implement policy, economic fluctuations (e.g. particular EU funding keys) and changing sites of policy debates (between civic and political institutions), we can see more clearly how elemental transnational technocracies do not just facilitate, but also shape memory in peacebuilding processes and policy formation, and vice versa.

Bringing back the state in administrations of memory

So far we have argued that the coexistence of domestic and transnational frames are at the very core of contemporary memory dynamics and that structural factors are central to the production of cultural contents of remembrance. In this section, we develop this last point to bring the state back into memory studies, dissociated from the nation.

The theorization of the relation between memory and government involves a paradox.

From a mostly historian perspective, and following Pierre Nora's canonic work on Realms of memory (1996), the Nation-State is said to have always taken part in the construction of a collective memory. However, since the 1980s nation-state memory is said to be disappearing as it has been described as fragmenting and losing ground as a central organizing actor at the benefice of these "multidirectional", local, transnational or diasporic memories [START_REF] Nora | Présent, nation[END_REF][START_REF] Rothberg | Multidirectional memory. Remembering the holocaust in the age of decolonization[END_REF]. At the same time, and this time from the perspective of public administration and governance, during the last twenty years, many states have begun, for the first time, to implement dedicated public administrations and institutions in charge of 'memory', 'history' or 'the past', depending on the national context and language tradition. If we look at the French case, which will guide us in the following pages, 'Memory' appeared for the first time in the labelling of a new government in 2014 with the creation of a 'Ministry of Veterans Affairs and Memory'. This coincidence invites us to investigate the relationship between memory and state from a different perspective, moving from this mainstream historian reading of it to a far more normalized public policy and government studies approach [START_REF] Gensburger | Comprendre la multiplication des 'journées de commémoration nationale': étude d'un instrument d'action publique de nature symbolique[END_REF]. To do so, we will first identify where memory studies and theory of the state failed to meet. Second, we will demonstrate how fruitful encounter may be for both of the field as a way to think forward the core contemporary issue of political legitimation and participation. This demonstration will consider the importance of taking the idea of bureaucracy of memory seriously and the fact that memory policies are not always, and even not mainly about governing the representations of the past but about framing the social institutions and interactions in the present. Here the notion of policy feedback may be useful to ask us what memory policies can be about, beyond the past?

Memory and State: a missed encounter

Claiming that most of memory studies forgot to take the state and its organization seriously can come as a surprise. Large parts of the pioneering work in memory studies have indeed covered national memory issues and, in most of the case, did so through the study of politics. However, our argument here is that many of these studies have overvalued the place of the nation because they have not sufficiently accounted for the specific structures of the states.

Numerous authors have been paying interest to the 'politics of memory', 'politics of the past', 'official uses of the past', 'state commemorations' or 'politics of history', in countries with democratic as well as authoritarian regimes. However most of these works focus on the 'politics of memory' of a particular past or key events, most often labelled as 'traumatic' or 'violent' such as the holocaust, the Pinochet regime, the first World War, slavery or ethno-national conflicts. In doing so, these works examine 'narratives', 'texts', 'storytelling' and other linguistic or visual contents and representations [START_REF] Kansteiner | Finding meaning in memory: A methodological critique of collective memory studies[END_REF]. This perspective led to take for granted the fact that memory policies are about controlling the representation of the past to govern the present and orient the future. They pay scant attention to the state, its organization and its government and do not address how memory has become, both nationally and transnationally, a category of state intervention as such.

Consequently, the existing literature has been interested mainly in what is said or shown of this past. Thousands of books and articles are dedicated to the study of the narrative content of speeches or exhibitions. Memory in its relation to government is first seen as content-related and remembrance public policies as transmission-driven with few critical perspectives. The fact that these politics of memory are about governing people's representations of the past is taken for granted.

The most recent works, however, have more fully taken into account these 'actors of memory' or 'memory entrepreneurs' [START_REF] Winter | War and remembrance in the twentieth century[END_REF][START_REF] Wüstenberg | Civil society and memory in postwar Germany[END_REF]. They are said to influence and lobby the State to advocate their vision of the past or to resist the imposition of the state official vision of history. But in these social conflicts over memory no equal attention is paid to the State actors they are interacting with. These barely go beyond prime minister or president, sometimes MPs, most often summoned through their public speeches [START_REF] Gavriely-Nuri | Collective memory as a metaphor: The case of speeches by Israeli prime ministers 2001-2009[END_REF][START_REF] Garcia | Il y avait une fois la France[END_REF][START_REF] Polletta | Legacies and liabilities of an insurgent past: Remembering Martin Luther King, Jr., on the house and senate floor[END_REF].

Bureaucracy and memory

So an increasing number of governments have been implementing public policies in the field of 'memory' and creating dedicated administrations and public agencies to channel these. But so far, this evolution has mostly been studied from the point of view of the different pasts commemorated, insisting more on the transnational dynamics than on the State organizations and transformations issues.

However, the concept of a public policy field or area can prove very useful to see this evolution differently. The study of memory as an area of public policy and as such as a category of state intervention may bring some new perspectives and better balance the role played by 'actors of memory'. The area of public policy forces the researcher to assess memory dynamics in the reverse way beyond thematic approaches such as politics of memory and 'memory of the Holocaust', 'memory of slavery' or 'colonialism' and so forth. Once we break with this dominant perspective, things appear in a very different light. The emergence of a memory field for administrations maybe, at least partly, a result of internal transformation of the states confronted with neo-liberal reforms and the evolution of some of its particularist clientele. Here, different situations, depending on each state historical construction, can be instrumental in creating a converging phenomenon.

In the French case, for example, the investment of governments in engaging with memory initiatives does not appear only, or even mainly, as a state response to social demands coming from memory entrepreneurs, committed to a multitude of different pasts.

Rather, they appear as the result of a Veteran Affairs crisis. Since the immediate aftermath of the First World War, the State has taken care of millions of former soldiers through the prolific and powerful Ministry of War Veterans and Victims (Ministère des Anciens Combattants et Victimes de Guerre, hereinafter MWVV)8 .

The interest of the French state in the public evocation and commemoration of the past is obviously not new. The intervention of governments and administrations in this field far precedes its constitution as an area of public policy. If the Second World War has often been seen as the founding event of the current memory framework [START_REF] Wieviorka | The era of the witness[END_REF], a detailed analysis of the state organization in the aftermath of the conflict indicates that by then the evocation of the past was not conceived as a category of state intervention but as one of the tools available for other areas of public policy such as foreign affairs, education, culture or veterans [START_REF] Gensburger | Does the French state conduct a politics of memory?[END_REF][START_REF] De Cock | Sur l'enseignement de l'histoire[END_REF]. In 1945, and following the First World War example, the management of the consequences of the war was mainly entrusted to the Ministry of War Veterans and Victims. Its main mission was 'reparation,' that is, meeting the needs of war veterans and supervising the creation and maintenance of war cemeteries and memorials. Its activity, which was not labelled with any specific term, was limited to the erection of memorial sites and the organization of commemorative ceremonies. The mourning and the reparation of direct damages were the main raison d'être of the MWVV. The writing of the War's history was assigned to a different office, the Second World War History Committee. Neither the MWVV nor the WWII History Committee discussed 'memory' as such, nor did they aim to promote it. While the first was meant to deal with living victims and help them to go on with their life, the second was supposed to work as historicizing the recent past. In 1960s, in the crossover between the two, the field of memory had not yet been opened.

Whereas in 1950 the MWVV took care of 7.5 million French veterans, in 1970 this number had dropped sharply, as veterans of the world wars aged and died. The high ranked civil servants of the ministry realized then that their numbers would gradually dry up, which could bring about the disappearance of the ministry itself. In the words of several ministry officials, it was urgent to find a new 'niche', one with the potential to replace living veterans as the focus of the ministry, and therefore enable it to carry on beyond their lifespan. This situation led the administration to develop a new area of public policy, under their supervision, in the field of 'memory' of wars and conflicts. To do so, the Ministry of War Veterans and Victims took advantage of the decentralization reform implemented by the Left, recently arrived in power in France, and capitalized on the departmental committees and the expertise of the MWVV in the co-management with non-profit organizations of veterans and their families. In the early 1980s, then, a department of veterans' affairs, eager to ensure its own survival, created a new field of activity, thus possibly giving rise to a new set of resources and a new area of activity for NGOs and actors of civil society around this new social issue of 'memory'. This becomes evident by shifting focus from the particular memories enabled in France to how memory was conceptualized as an area of public policy and a category of state intervention.

In 1997, a High Committee for Combatant Memory (Haut Conseil à la Mémoire Combattante), a new state agency, was created to draw, for the MWVV, what was henceforth systematically described as the public policy of memory and defined as 'actions in the fields of the public policy of memory of contemporary wars and conflicts, and of the promotion of memory spaces and historic monuments'. So when the MWVV was renamed in 2014, this choice of name institutionalized, at a governmental level, the administrative reorganization initiated some thirty-odd years before.

Moreover looking at the relation between state and memory through the concept of a public policy field or area leads the observer to consider the dynamic played in the memory boom by internal state organization dynamics and concurrence. In our case, the evolution of the MWVV took place in relation to other ministries and it is this global administrative dynamic which led to the emergence of the memory public policy field. One single example will be given. In the 1980s, while the concept of memory was promoted by the MWVV administration, the Ministry of Culture gave birth to the concept of 'celebration'. In 1974, it created a committee for National Celebrations, and such events would in turn be transformed over the 1990s and become institutionalized around the terms 'memory' and 'commemoration'. In 1998, barely a year after the creation of the High Committee for Combatant Memory in relation to the MWVV, the Ministry of Culture created its own 'high' structure: the state agency of the 'High Committee for National Celebrations'. 'Memory' as a category of public intervention became the subject of constant competition between administrations, giving substance to this new area of a public policy of memory. The very competition between the ministries in establishing memory as a field of policy thus significantly structured it as a field of intervention, as the ministries vied with each other for control over this emerging policy domain. This dynamic took such proportion that, in 2000, in its report on 'memory policy', the Court of Auditors of the French State deplored these overlaps and tensions between the Ministry of Culture and the MWVV. Still, a few years later, the High Committee for National Celebrations was renamed High Committee for National Commemorations, showing the Ministry of Culture's vindication of its own expertise, a gesture particularly aimed at the MWVV. In other words, what we see in this case is how the development of memory as a social issue appeared as a result of a competition between the offices of Culture and War Veterans rather than exclusively, and mainly, as a result of the frequently mentioned competition of Memories [START_REF] Sims | Rethinking France's « Memory Wars[END_REF].

This calls for an investigation of policies of memory from the point of view of the way diverse state actors conceive, negotiate, and compete over this issue, that is to say, the administrations of memory. The relationship between memory and politics has often been considered mainly through the lens of transmission of narratives, echoing the logic of the state in its propaganda and repressive power dimensions. To go on with a Michael Mann typology of state powers, memory appears here rather as a way to study the infrastructural power of the state [START_REF] Mann | The autonomous power of the state: its origins, mechanisms and results[END_REF]. The hypothesis can be made that, beyond transnational dynamics, several parallel state transformations can have been instrumental in leading to similar memory evolutions while starting from very different contexts [START_REF] Danilova | The politics of war commemoration in the UK and Russia[END_REF][START_REF] Volker | Caring for clients in a changing environment: The department of Veterans' Affairs[END_REF]).

Moreover, it invites us to draw on memory issues to think of news ways to conceptualize the very notion of political regimes and to build inter-state comparison from a transnational memory dynamic (For a start in this direction, see [START_REF] Lebow | The future of memory[END_REF]and Gensburger 2016a).

New public management and policy feedbacks 2002). However, when studied trough a classic public policy perspective, the current governmental investment in memory implies a specific relation between public administration, scientific experts and citizens' participation.

The French State has regularly relied on dedicated commissions to choose the twelve new national memory days which have been instituted in France since 2000. These committees are partly made up of historians, labelled 'memory experts', and partly 'memory stakeholders'. Several times, this search for consensus and the difficulty to balance knowability and governability has led to the decision to commemorate not the events themselves but the previous commemoration of the event.

In 2003, the commission in charge of the contemplated commemoration of the Algerian war was dissolved without any agreement among its members. The French State decided then that the national day devoted to the memory of the dead during this war would be December 5. This date evokes nothing else than the inauguration of a National Monument in honor of the Algerian War veterans, which took place on December 5 2002. On May 10 2006, France celebrated the first national day devoted to the memory of the slave trade, slavery and its abolition. In the same way, May 10 does not refer to any event in the history of slavery but to the day in 2001 when the French senate, unanimously and solemnly, made the slave trade and slavery a crime against humanity. Here then the public policies of memory are framed more by previous administrations of memory than by any particular historical event.

These examples urge us to consider how memory politics are not always and sometimes not mainly about knowability and contents but first and foremost about the relationship they create between government and people, which is to say: about governability. It leads us to pay attention to memory as a social field and to consider how the first impact of memory policies may not be about transmission but mobilization and legitimation. It creates a new field where memory becomes a social resource to fight for and through which to engage in a relation with this very same state.

At this point, a public policy analysis perspective on memory invite to ask what memory public policies do beyond acting on representation of the past, which they do far less than we might think [START_REF] Klein | On the emergence of memory in historical discourse[END_REF]. Here the concept of policy feedback [START_REF] Mettler | Bringing the state back in to civic engagement: Policy feedback effects of the G.I. Bill for World War II veterans[END_REF]) may be useful since it draws attention to the impact of public policy beyond what they are made for or at least said to be made for. In our case, we can hypothesis that one of the emerging policy feedbacks of memory policies seems to foster some peculiar vision of the social relations between groups; who is concerned by memory and who is not. In so doing, they create circles of legitimation of social actors in their relation to the state and, reciprocally, by mobilizing some people more than others they can foster antagonistic relations to the state and increase and limit its legitimation at the very same time, especially in a world of social and economic inequalities. Here our interrogation goes from an interest in the administration of memory to an attention to what is administered through memory. This reversal of perspective is the horizon of the following texts which delimitate a new research agenda both for political science and memory studies.

Introducing the issue

The first two articles bridge political science and memory studies through the study of two local manifestations of transnational memory making. Linda Hasunuma and Mary McCarthy offer new perspectives on the recent controversies surrounding the memorialization of South Korea's comfort women in several American cities. Shifting the focus from bilateral historical grievances and tensions between the national governments of Japan and South-Korea, it enables us to contemplate the grassroots and transnational politics involved in the siting of these monuments in a land that was neither home to victim nor perpetrator.

While these issues are often looked at as manifestations of transnational relations, the authors stress the importance of domestic factors such as the growing political consciousness and engagement in American civic life. Jacco Visser examines the ways in which Bangladesh' Sheikh Mujibur Rahman 'Father of the Nation' is remembered at local, national and international scales and places. In this case, the local scale is a specific politico-cultural community in London where the erection of a bust of Sheikh Mujib took place on the initiative of long-distance nationalists. This article reveals how transnational policies shape local commemorative practices and contested relationships with the past, which persist both in Bangladesh and in London. In doing so, it stresses the role played by lower-level policymaking decisions taking place outside the targeted nation state's political framework as well as transnational heritage discourses. Finally, the dialogue between these two first articles also draws attention to commemoration as an integration device for making citizens and subjects, but with different aspirations for political association and community. The two cases also display different gender dimensions since women of civil society are a core dynamic in the first case, both as memory activists and people to remember, while the second case is centered around a patriarchal memory (of 'the father of the nation'), and though memory runs through women as dynastic political figure heads (descending from 'the father of the nation'), the commemorative practice on the ground is performed mostly by men. Sarah Maddison's and Birgitte Schepelern Johansen and Thomas Brudholm's contributions both explore the legal administration of memory in terms of agonism. Sarah Maddison demonstrates the limits of the administration of memory in a particular form of political culture, that is, the settler colonial society, in Australia. She recommends moving from insisting on coupling memory, conflict resolution, and reconciliation, to insisting on policies that allow for constitutional pluralism and the persistence of unsettled memory and history conflicts. Here, there can be no easy or final integration of pasts and political communities in nation-state terms. Policies of reconciliation and administration of memory must then cease to be about closure and instead keep open political spaces in which contested views about the past may be engaged. In their article, Birgitte Schepelern and Thomas Brudholm study how policy complexes give shape to each other, particularly in the way antihate crime policy and Holocaust remembrance are interlinked and merged in metamorphorising. Here the administration of remembrance is not focused on closure but, on the contrary, is expected to influence societal and individual behavior in the present and the future through narrative, practical, institutional transfers from one policy domain to another. However, in this case also, the authors point out the limits of this administration of memory as a way to manage antagonism in contemporary Europe and calls, in their own way, for a form of agonism in this case, also. This tension between antagonism and agonism is again omnipresent in the two last articles. But in these cases, from an international relations perspective. Lea David explores how memory has become a crucial category through which human rights regimes work in international administrations of memory. Particularly, in former conflict zones and potential EU candidate countries. In this, her article brings together nascent literatures in international relations and memory studies on the securitization of memory, through different legal instruments and mandates. Using a case from Bosnia-Herzegovina, she seeks to uncover how external pressures to adopt memorialization policies in fact arise from ontological securityseeking at the international level and how this can come to entrench local and national divisions along ethnic lines. Valérie Rosoux asks very similar questions about how former enemies can turn the page and move forward, in her comparative article about Franco-German and Franco-Algerian relations. Her article studies the administration of post-war memory through analyzing the bilateral negotiation processes devoted to addressing the legacies of the past. Rather than reducing the notion of public administration to the mere implementation of

  implementation was effected largely by community-based organisations in Northern Ireland, conducting projects on the basis of local interests and needs. Importantly, while a first wave of projects were conducted prior to the HTR consultation described above, HTR has also given firmer definition to those existing practices by establishing auditing parameters[START_REF] Kelly | Storytelling audit. Belfast: Healing Through Remembering[END_REF], conducting consultations, and issuing guidelines for future storytelling projects(HTR Conversation Guide 2008). At the supranational level, EU peacefunding frameworks have further shaped a second wave of processes and products in establishing Key Performance Indicators, focused on building positive relations at the local level and reconciling communities in the Peace III programme (running from 2007-2013). Demonstrating the constant transnational dynamics at play, the operational term 'reconciliation' in EU funding frameworks was defined by Northern Ireland academics Brandon Hamber and Grainne[START_REF] Hamber | A working definition of reconciliation[END_REF], and projects were selected on the basis of meeting criteria set out in that definition as well as measured according to a new impact framework called Aid for Peace, developed by multinational firm PriceWaterhouseCoopers (SEUPB 2013). In other words, the administrations of memory involved in the storytelling projects arose in a dialogue between transnational and local social, political and economic interactions, both in a horizontal and vertical sense. At the same time, this dialogue was framed within the specific context of Northern Irish political culture.Linking to the national and governmental level, it is significant that the Northern Ireland Government itself did not begin to conceptualise strategies of reconciliation until 2013, when the strategy 'Together: Building a United Community Strategy' was launched (OFMDFM 2013), leaving work on reconciliation up until that point largely without nationalpolitical leadership. We might argue that, while the absence of overarching policy seriously complicates dealing with the past in legal terms, it has at the same time left space open for more 'agonistic' and 'reflective' memory modes to flourish in storytelling projects[START_REF] Mcquaid | Notes on studying public policies of memory: The parades commission in Northern Ireland and the institutionalization of memory practices[END_REF] Cento-Bull & Lauge Hansen 2015). That the past was left out of the peace agreement also means that it was not fully captured by the hegemonic national narratives and conflict parties privileged and institutionalized through powersharing. Outside the Agreement, civic attempts at dealing with the past have been more malleable to the influence of changing peace building norms in the past 20 years, notably in relation to 'the local turn', 'transitional justice', UN resolution 1325 (on gender inclusion in peace processes), and UN discussions on history teaching and memorialization processes (A/HRC/28/36 2014).

Herweg (2016) defines a policy community as a 'mainly loose connection of civil servants, interest-groups, academics, researchers and consultants (the so-called hidden participants), who engage in working out alternatives to the policy problems of a specific policy field' (2016, p. 132)

HTR is a cross community organisation working with people from diverse backgrounds both within and outside of Northern Ireland. Their work contributes to, and informs the public debate about dealing with the violent past in Northern Ireland, not least in terms of developing policy. It matches the definition of a policy community.

Importantly, the name of the Ministry has changed over time, but for brevity and clarity we will apply this most recent iteration.

If public policies of memory are conceived as the products of the infrastructural power of the state, how can we assess its impact? How can we grasp memory beyond the idea of a transmission of narrations of the past? In France as elsewhere, the development of these administrations of memory has taken place at the same time as the diffusion of new public management, which has been studied in depth by political science in the past years. In this evolution, the recent transformation of the state goes hand in hand with the conceptualization of public policy with aims and formal indicators to assess if these goals have been achieved.

However, the development of formal memory public policies seemed to have led to the limit of this mechanism. How can you estimate the impact of memoryon individuals or in its collective dimension? How can you measure reconciliation and peace resulting from memory?

Again, the French context gives us the opportunity to move forward in this direction.

In 2006, the French state broke with the tradition of expenditure-oriented budgets by drawing up a program budget based on objectives and performances. Missions were enumerated, corresponding to the State's major public policies. 'Memory policy' has since been included among these missions. And yet, up to now, in this single case, no objective and performance indicators have been defined by the state. Here bringing the state back into memory studies propels us to move from a knowability to a governability approach of the politics of memory [START_REF] Andersson | The future of the world. Futurology, futurists, and the struggle for the post Cold War imagination[END_REF]. More than cosmopolitism or world ethics, it is, on the contrary, neoliberalism and the crisis of representative democracy that comes with it, which may be one of the main reasons for the development of the contemporary memory boom.

Considering memory from a public policies analysis perspective finally invites us to reconsider what memory policies are about. Most of the work on memory and politics focuses mainly on the uses of the past that the government action is supposed to transmit and promote, through museums, school curricula, remembrance days or many other tools (Müller government policies, she suggests broadening the perspective to consider a mix of policy areas and insists, as Lea David, to move beyond a sharp distinction between 'top-down' and 'bottom-up' approaches of both public policies and memory studies.


A Labrousse

B Dagens

R Brenot

B Lavigne

S Squedin

B Martin

S Fabre

M L L Nielsen

M Renaud

Standard mode 40Gbit/s performance analysis of the evanescent coupling "active-passive" Mach-Zehnder interferometers for all-optical regeneration

come

Standard mode 40Gbit/s performance analysis of the evanescent coupling "active-passive" Mach-Zehnder interferometers for all-optical regeneration

Introduction:

Data signal impairments, due to switching nodes [START_REF] Berthelon | Design of a cross-border optical core and access networking field trial : first outcomes of the ACTS-PELICAN projet[END_REF] and optic fiber transmission links [START_REF] Bigo | All-optical fibre signal processing and regeneration for soliton communications[END_REF], make the all-optical 3R regeneration an essential data processing function for the future all-optical networks.

Cascaded all-active SOA (Semiconductor Optical Amplifier)-based Mach-Zehnder interferometers, with high Input Power Dynamic Range (IPDR) [START_REF] Janz | Integrated all-active Mach-Zehnder wavelength converter with -10dBm signal sensitivity and 15dB dynamic range at 10Gb/s[END_REF], have shown excellent regenerative capabilities in a recirculating loop up to 40Gbit/s in differential scheme [START_REF] Lavigne | Cascade of 100 optical 3R regenerators at 40Gbit/s based on all-active Mach-Zehnder interferometers[END_REF]. New modular devices, from the evanescent coupling "active-passive" integration scheme, realize 40Gbit/s wavelength conversions in standard mode with a lower total consumption and without detectable bit error floor, thanks to structural modifications of their active zones [START_REF] Dagens | New modular SOA-based active-passive integrated Mach-Zehnder interferometer and first standard mode 40Gb/s all-optical wavelength conversion on the C-Band[END_REF]. A high IPDR is important to ease the insertion of those devices into the transmission systems and a high noise resistance prefigures important regenerative capabilities. Both parameters for those new devices are studied at 40Gbit/s in standard mode in this letter.

40Gbit/s data signal IPDR: The data signal IPDR was measured and compared at 40Gbit/s for two configurations of the evanescent coupling "active-passive" SOA-based MZI [START_REF] Dagens | New modular SOA-based active-passive integrated Mach-Zehnder interferometer and first standard mode 40Gb/s all-optical wavelength conversion on the C-Band[END_REF]: the two-SOAs device which includes only the two conversion SOAs, and the four-SOAs device which includes two more peripheral SOAs placed on the data signal entries. Only the standard working mode (the data signal is injected into a single branch of the MZI (no differential mode)), and the co-propagation scheme (the data and the continuous signal propagate in the same way) are considered (see Fig. 1). The modulation and detection set up are identical to the ones described in [START_REF] Dagens | New modular SOA-based active-passive integrated Mach-Zehnder interferometer and first standard mode 40Gb/s all-optical wavelength conversion on the C-Band[END_REF].

The penalty was noted for a 10 -10 BER (Bit Error Rate) of the converted signal and the input data signal power was varied from 0dBm to 9dBm, depending on the device. The threshold voltage and the delay of the optoelectronic receiver were unchanged for each measurement. For the device with peripheral-SOAs, conversions were realized from 1552nm to 1560nm with a 13dBm continuous input power, a 900mA injection current in the conversion-SOA, and for the device without peripheral-SOAs from 1552nm to 1555nm with a 9dBm continuous input power and a 750mA current. Results and the data signal peripheral-SOA current corresponding to each input data signal power for the device with the peripheral-SOAs are reported on the Fig. 2.

Without any control of the peripheral-SOA, the data signal IPDR corresponding to a 1dB excess penalty is close to 1.5dB for both devices. The optimal input data signal power of the four-SOAs device is 2dB more important than for the two-SOAs device, because of excess insertion losses possibly due to its two extra active-passive transitions. The data signal IPDR is attractively increased up to more than 8dB when the level of the peripheral-SOA current is adjusted, in order that its gain compensates for the input power fluctuations of the data signal. This is one great asset of the presence of the peripheral-SOAs.

Noise resistance and peripheral-SOAs current at 10Gbit/s: The noise resistance of the MZI with peripheral-SOAs was evaluated at 10Gbit/s, when varying the level of the data signal peripheral-SOA current from 50mA to 100mA. For each value of current, the power of the data signal was adjusted and the minimum input data signal OSNR (Optical Signal Noise Ratio), under which the BER floor of the converted signal was greater than 10 -9 , was determined (see Fig. 3). A 0.1nm resolution for the optical spectrum analyser was used to measure the OSNR. Conversions were realized from 1552nm to 1540nm with a 10dBm input continuous signal power. In order to control the OSNR of the input data signal, the latter was coupled with the ASE (Amplified Spontaneous Emission) of an EDFA (Erbium Doped Fiber Amplifier), which passed through a variable attenuator, thanks to a 50:50 coupler. The level of the coupled ASE power fixes the OSNR.

When the current of the peripheral-SOA differs from the range value 55mA-60mA (around its transparency point), the tolerated minimum input OSNR increases. Therefore, the noise resistance of the device decreases since a less noisy data signal is necessary to make the same error rate. When its peripheral-SOA current is increased, the ASE power propagating along the whole structure is more important. When it is decreased, the noise figure of the peripheral-SOA increases, that can mainly explain the signal impairment. This happens for instance when the peripheral-SOA current is changed to compensate the input data signal power fluctuations. So the variation of the peripheral-SOA current, which allows to increase the IPDR of the device, induces a decrease of its noise resistance. Thus, there is a compromise to find between a high IPDR and a high noise resistance.

Noise resistance at 40Gbit/s: The excess penalty for a 10 -10 BER of the converted signal against the data signal noise was measured at 40Gbit/s in the optimum conditions, with the 55mA peripheral-SOA current. Results are shown on the Fig. 4.

The input data signal OSNR is measured with a resolution of 1nm in order to integrate all the data signal power.

Anyway the presented results correspond to a 0.1 nm resolution in order to ease comparison with usual measurements. The same operating conditions as for the IPDR measurement at 40Gbit/s are applied, with a 1.9dBm input data signal power. The experimental set up used to degrade the input data signal OSNR is unchanged. The noise tolerance of the device is much less important at 40Gbit/s than at 10Gbit/s. A 1dB excess penalty is reached for a 29dB OSNR at 40Gbit/s, compared to only 20dB at 10Gbit/s. This degradation of the noise resistance is not due to the device itself, but is mainly inherent to the increase of the bit rate (four times).

The noise receiver depends directly on it and the bit rate increase decreases the bit energy detected by the receiver. Thus, the noise resistance capability of a single device decreases with the bit rate. Nevertheless, 3R regeneration capabilities at 40Gbit/s have already been proved by cascade experiments via the use of a recirculating loop, with a regenerator formed by one SOA and one two-SOAs MZI [START_REF] Lavigne | Low input power all-optical 3R regenerator based on SOA devices for 42.66 Gbit/s ULH WDM RZ transmissions with 23dB span loss and all-EDFA amplification[END_REF]. Good regeneration capabilities at 40Gbit/s have been shown with those new devices, which turn out to be more attractive: they require less important injection currents and are more easy to handle.

Conclusion:

Thanks to high bit rate capabilities, the IPDR and the noise resistance of evanescent coupling "active-passive" MZIs have been measured for the first time at 40Gbit/s in standard mode and without clock injection. The integration of peripheral-SOAs increases attractively their IPDR, at more than 8dB. Nevertheless, the existence of a compromise between a high IPDR and a high noise resistance has been established.

A decrease of their noise resistance is noted at 40Gbit/s, inherent to the bit rate increase between 10Gbit/s and 40Gbit/s. Nevertheless, the excellent regeneration capabilities at 40Gbit/s have been demonstrated with these new devices, including furthermore a reduced electrical consumption and an easier handling.

Figure captions

Fig. 1 MZI in standard working mode and co-propagation scheme. Conversion and peripheral-SOAs are illustrated. Ps, s: data signal input power and wavelength, Pc, c: continuous signal input power and wavelength.

Fig. 2 Data signal input power dynamic range (IPDR) @40Gbit/s of evanescent coupling "active-passive" MZIs, and the corresponding current of the peripheral-SOA I'4.

-: MZI without peripheral-SOA : MZI with peripheral-SOA, without current control of the peripheral-SOA : MZI with peripheral-SOA, with current control of the peripheral-SOA : Current control of the peripheral-SOA Fig. 3 Noise resistance @10Gbit/s against the peripheral-SOA current I'4.

Fig. 4 Excess penalty @40Gbit/s against input data signal Optical Signal Noise ratio (0SNR) (dB@0.1nm@10Gbit/s) I 4 ' (mA) (dB@40Gbit/s) OSNR@0.1nm

  Figure 2

  Figure 4


Polarity-preserving SOA-based wavelength conversion at 40 Gb/s using band-pass filtering M.L. L Nielsen, B. Lavigne, B.

Polarity-preserving SOA-based wavelength conversion at 40 Gb/s using band-pass filtering M. L. Nielsen, B. Lavigne, B. Dagens All-optical wavelength conversion is demonstrated at 40 Gb/s, using a single SOA and a band pass filter. The scheme is very simple, requires an extremely low switching energy of ~ 3 fJ, and preserves data format and polarity.

Introduction: Introducing all-optical wavelength conversion (AOWC) capabilities in WDM network nodes may reduce cost and footprint by circumventing optical-electrical-optical (OEO) conversion, while adding the flexibility of wavelength routing. However, even the most promising integrated, semiconductor optical amplifier (SOA)-based wavelength converters, as e.g. the delayed-interference signal converter (DISC) [START_REF] Leuthold | All-optical wavelength conversion between 10 and 100 Gb/s with SOA delayed-interference configuration[END_REF], or Mach-Zehnder interferometer (MZIs) [START_REF] Dagens | New Modular SOA-based activepassive integrated Mach-Zehnder interferometer and first standard-mode 40 Gb/s all-optical wavelength conversion on the C-band[END_REF], rely on the control of at least two bias currents (SOA bias or phase tuning currents) for optimising the operating conditions. Moreover, to compensate for the inherently low input power dynamic range (IPDR) of these devices, an additional SOA is needed at the data signal input [START_REF] Dagens | New Modular SOA-based activepassive integrated Mach-Zehnder interferometer and first standard-mode 40 Gb/s all-optical wavelength conversion on the C-band[END_REF]. This adds up to at least three currents, which need to be tuned to accommodate changes of wavelengths, input signal quality, etc. In this letter we report on a very simple AOWC, based on a single SOA and an optical band-pass filter (BPF). The converter operates at 40 Gb/s, preserves the data polarity and RZ format, and does not introduce patterning effects. The single bias current allows for very simple control and stable operation, and in a recent report of a similar OAWC design [START_REF] Leuthold | All-Optical Wavelength Converter Based on a Pulse Reformatting Optical Filter[END_REF], an open loop IPDR of 11 dB indicates that control of input power fluctuations may not be necessary. We find that the best performance of the AOWC is obtained for a data signal switching energy of only 3 fJ. To our knowledge, this is the lowest switching energy ever reported for polarity-preserving wavelength conversion at 40 Gb/s. The low optical power consumption may save the cost of an Erbiumdoped fibre amplifier (EDFA) at the input of the AOWC.

Principle and experimental setup

The principle of operation of the wavelength converter can be understood from the experimental setup in Fig. 1: a gain-switched DFB laser (GS-DFB) emits a 10 GHz train of ~7 ps wide pulses at a wavelength of 1552 nm, which is then modulated with a PRB sequence of word-length 2 31 -1 before being multiplexed to 40 Gb/s in a passive fibre-based interleaver. The 40 Gb/s RZ data signal is combined with a continuous wave (CW) probe at 1545.08 nm, and launched into the strained-bulk SOA, which is 1 mm long, biased at 300 mA, and has a large optical confinement factor of 0.6. Measured at the SOA input, after the 3 dB coupler, the data and probe average powers are -12.25 dBm (~ 3 fJ/data pulse) and -3.0 dBm, respectively. Inside the SOA the probe is cross-gain modulated (XGM) and thus polarity-inverted, as well as crossphase modulated (XPM) by the data signal. The leading edge of the modulated probe is shifted towards lower frequencies (red-shifted), whereas the trailing edge is shifted towards higher frequencies (blue-shifted). Due to the low data-to-probe power ratio of -9.25 dB XGM is quite inefficient. This is not the case for XPM, however, and thus a significant broadening of the probe spectrum can be observed. At the output of the SOA, a tuneable grating filter with a bandwidth (FWHM) of 0.22 nm is centred at 1544.58 nm, i.e. detuned 0.5 nm to the blue side of the probe carrier wavelength. The filter selects the blue-shifted sideband of the probe, converting the phase modulation into amplitude modulation, while efficiently suppressing the CW carrier wavelength. Suppressing the carrier corresponds to suppressing the DC content of the polarity inverted probe waveform. As indicated in Fig. 1, this restores the non-inverted polarity of the converted signal, which is important for obtaining good transmission properties [START_REF] Durhuus | All-optical wavelength conversion by semiconductor optical amplifiers[END_REF]. The wavelength converted signal is amplified in an EDFA, and demultiplexed into the four 10 Gb/s tributaries using an electro-absorption modulator (EAM), before bit error-rate (BER) measurements.

Similar schemes have been used to realise polarity-preserving wavelength conversion at bitrates up to 20 Gb/s [START_REF] Patrick | 20 Gbit/s wavelength conversion using semiconductor nonlinearity[END_REF]. Recently, a microelectromechanical system (MEMS) based filter was used to shape the probe output of a 2 mm long SOA in a 40 Gb/s experiment [START_REF] Leuthold | All-Optical Wavelength Converter Based on a Pulse Reformatting Optical Filter[END_REF]. In that demonstration, the best BER performance for polarity-preserving operation was obtained for an average data input power of 2 dBm, measured at the SOA input. Analogous approaches have been taken to realise non-linear fibre based wavelength converters exploiting ultra-fast, but very power-inefficient, fibre non-linearities [START_REF] Olsson | A simple and Robust 40 Gb/s Wavelength Converter Using Fiber Cross-Phase Modulation and Optical Filtering[END_REF].

Experimental and modelling results:

The amount of spectral broadening induced by XPM is seen in Fig. 2 by comparing the probe spectra before filtering, with and without the data power turned on. Significant spectral broadening is introduced by the small average data power of -12.25 dBm, while the modulation of the gain is kept at a minimum. This reduces detrimental pattern effects, and consequently the scheme is expected to benefit from a large phase-gain coupling (parameter). Fig. 2 also shows the BPF characteristic, and the corresponding probe spectrum after filtering. The probe power after the filter is only -21 dBm, measured in a large optical bandwidth. A low output power is inherent to the scheme because most of the power is contained in the 'carrier peak'.

However, using a filter with a steeper slope and higher peak-to-background rejection ratio, a smaller filter detuning would be required to sufficiently suppress the carrier, thus increasing the transmitted power.

Extensive modelling, using a detailed multi-section SOA model, has been carried out to compare with experimental results. The physical input parameters to the model: SOA dimensions, optical confinement factor, bias current, input powers, filter shape, etc., are identical to the experimental parameters. Fig. 3 shows a comparison between experimental (left column), and simulated (right column) eye diagrams of the converted signal. The upper, middle, and bottom rows correspond to filter detunings of -0.5, -0.3 nm, and 0 nm, respectively. As observed, the agreement is very good, qualitatively, as well as quantitatively. For the optimum filter detuning of -0.5 nm, the extinction ratio is ~15 dB, and the data polarity and the RZ format is clearly preserved. Fig. 4 shows the BER performance of all four 10 Gb/s tributaries of the input data signal at 1552 nm and the wavelength converted signal at 1545 nm. The power penalty at BER = 10 -9 ranges between 1.7 and 2.8 dB for the best and worst tributary, respectively, and is believed to be primarily due to ASE noise added by the EDFA after the filter. The fast response of the converter is clear from Fig. 5, which compares a part of the input data pattern to the pattern of the wavelength converted signal. The only observable difference is the pulse width, which has increased to ~15 ps, measured with a 50 GHz photo diode.

Conclusion

In this letter we have demonstrated a very simple all-optical wavelength converter based on a single 1 mm long SOA and a band pass filter. The converter operates at 40 Gb/s, and preserves the RZ data format and polarity, using only ~ 3 fJ of switching energy per data pulse.

Figure captions : Fig. 1 .Fig. 2 .Fig. 4 .

 :124 Figure captions:

Fig. 5 .Figure 1 .

 51 Fig. 5. 40 Gb/s data patterns. Up: input at 1552 nm. Down: output at 1545 nm

Figure 5

 5 Figure 5.


The Determination of the Equilibrium Exchange Rate in a Simple General Equilibrium Model

Cuong Le Van, Cécile Couharde, Thai Bao Luong

To cite this version:

Cuong Le Van, Cécile Couharde, Thai Bao Luong. The Determination of the Equilibrium Exchange Rate in a Simple General Equilibrium

Model. 2004. halshs-03331130