Revealing Carrier-Envelope Phase through Frequency Mixing and Interference in Frequency Resolved Optical Gating

We demonstrate that full temporal characterisation of few-cycle electromagnetic pulses, including retrieval of the carrier envelope phase (CEP), can be directly obtained from Frequency Resolved Optical Gating (FROG) techniques in which the interference between non-linear frequency mixing processes is resolved. We derive a framework for this scheme, defined Real Domain-FROG (ReD-FROG), as applied to the cases of interference between sum and difference frequency components and between fundamental and sum/difference frequency components. A successful numerical demonstration of ReD-FROG as applied to the case of a self-referenced measurement is provided. A proof-of-principle experiment is performed in which the CEP of a single-cycle THz pulse is accurately obtained and demonstrates the possibility for THz detection beyond the bandwidth limitations of electro-optic sampling.Comment: 7 pages, 4 figures. To be submitted for publication in Optics Express, January 201

Comments on the September 29, 2014 FSB Consultative Document, ‘Cross-Border Recognition of Resolution Action’

This CIGI Paper No. 51 was released on December 3, 2014 by the Centre for International Governance Innovation (CIGI) as a response to the Financial Stability Board’s (FSB) Consultative Document, “Cross-Border Recognition of Resolution Action.” Principally authored by CIGI Senior Fellow Steven L. Schwarcz (who works with the think tank’s International Law Research Program), the Paper comments on the policy measures proposed by the FSB, an international body that monitors and makes recommendations about the global financial system, to address the cross-border legal uncertainties of troubled systemically important financial firms. In that context, the Paper explains why a statutory approach is more effective than a contractual approach at removing obstacles in cross-border resolutions of those firms, and thus a better method to achieve financial stability. The Paper also recommends that the FSB establish a working group on statutory mechanisms for the cross-border resolution of financial firms

Rethinking the Concept of Community

Traditionally, historians have preferred to rely on “common sense” approaches to the meaning of community, but such definitions, emphasizing the ideas of a shared place and a static, self-contained entity, are simply inadequate for historical research and writing. Three elements are fundamental to understanding the historical significance of community: community as imagined reality, community as social interaction, and community as a process. An interdisciplinary approach to this question takes into consideration the thinking of social scientists and humanists on the importance of space and networks in social life. The historical study of community, one that embraces both cultural and spatial perspectives, has much to benefit from and much to contribute to this ever-growing and evolving body of work. As they have done with such concepts as “the family” and “the nation”, historians must make “community” a problem to be studied, discussed, and debated.Traditionnellement, les historiens ont préféré définir la notion de communauté par le « bon sens », mais de telles définitions, qui soulignent l’idée d’un lieu partagé et d’une entité statique autonome, sont tout simplement inadéquates pour la recherche et l’écriture historiques. Notre compréhension de l’importance historique de la communauté repose sur trois éléments fondamentaux : la communauté comme une réalité imaginée, la communauté comme une interaction sociale et la communauté comme un processus. Une approche interdisciplinaire de cette question tient compte de la pensée des spécialistes des sciences sociales et humaines quant à l’importance de l’espace et des réseaux dans la vie sociale. L’étude historique de la communauté, qui englobe tant les perspectives culturelles que spatiales, a beaucoup à gagner de ces travaux sans cesse grandissants et toujours en évolution et beaucoup à y apporter. Comme ils l’ont fait pour des concepts tels que « la famille » et « la nation », les historiens doivent faire de « la communauté » un problème à étudier, à discuter et à débattre