\u3cem\u3ePer Ardua Ad Astra\u3c/em\u3e: A Concicise Guide to Canadian Personnel Records and RCAF Service Information of the Second World War

The motto of the Royal Canadian Air Force—per ardua ad astra—through adversity to the stars—might also serve as an apt expression when beginning research on individual Canadian airmen or airwomen of the Second World War. Without a guiding-hand, the first-time researcher is likely to experience some considerable “adversity” before locating their “stars.” This note introduces the key records and published sources for documenting those individuals who served with the Royal Canadian Air Force during the Second World War, as well as directions for locating the records of those Canadians who served in related air elements during the conflict. Many archival records and library sources give some information about these individuals; this note is limited to official records, or to those records compiled from official sources, that are held by the major Canadian and Commonwealth institutions which have the mandate to provide such essential wartime documentation

Lorenz-Mie theory for 2D scattering and resonance calculations

This PhD tutorial is concerned with a description of the two-dimensional generalized Lorenz-Mie theory (2D-GLMT), a well-established numerical method used to compute the interaction of light with arrays of cylindrical scatterers. This theory is based on the method of separation of variables and the application of an addition theorem for cylindrical functions. The purpose of this tutorial is to assemble the practical tools necessary to implement the 2D-GLMT method for the computation of scattering by passive scatterers or of resonances in optically active media. The first part contains a derivation of the vector and scalar Helmholtz equations for 2D geometries, starting from Maxwell's equations. Optically active media are included in 2D-GLMT using a recent stationary formulation of the Maxwell-Bloch equations called steady-state ab initio laser theory (SALT), which introduces new classes of solutions useful for resonance computations. Following these preliminaries, a detailed description of 2D-GLMT is presented. The emphasis is placed on the derivation of beam-shape coefficients for scattering computations, as well as the computation of resonant modes using a combination of 2D-GLMT and SALT. The final section contains several numerical examples illustrating the full potential of 2D-GLMT for scattering and resonance computations. These examples, drawn from the literature, include the design of integrated polarization filters and the computation of optical modes of photonic crystal cavities and random lasers.Comment: This is an author-created, un-copyedited version of an article published in Journal of Optics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

The collisional frequency shift of a trapped-ion optical clock

Collisions with background gas can perturb the transition frequency of trapped ions in an optical atomic clock. We develop a non-perturbative framework based on a quantum channel description of the scattering process, and use it to derive a master equation which leads to a simple analytic expression for the collisional frequency shift. As a demonstration of our method, we calculate the frequency shift of the Sr$^+$ optical atomic clock transition due to elastic collisions with helium