WDM-compatible polarization-diverse OAM generator and multiplexer in silicon photonics

Spatial multiplexing using orbital angular momentum (OAM) modes is an efficient means of scaling up the capacity of fiber-optic communications systems; integrated multiplexers are crucial enablers of this approach. OAM modes are circularly polarized when propagating in a fiber, however, OAM generators previously demonstrated in silicon photonics use locally linearly polarized emitters. Coupling from multiplexers to fibers in those solutions results in extra loss and complexity. Moreover, many of those solutions are based on resonator structures with strong wavelength dependence, and are thus incompatible with wavelength-division multiplexing (WDM). We experimentally demonstrate on-chip generation and multiplexing of OAM modes using an array of circularly polarized 2D antennas with wide wavelength coverage. The proposed device was implemented on the standard 220-nm silicon-on-insulator platform. Optical vortex beams with OAM orders ranging from -3 to +3 in both left and right circular polarization states were generated from the same aperture across a wavelength range of 1540 nm to 1557 nm. This device could serve as a multiplexer or demultiplexer for up to 12 information bearing channels coupling into a

Roadmap on spatiotemporal light fields

Spatiotemporal sculpturing of light pulse with ultimately sophisticated structures represents the holy grail of the human everlasting pursue of ultrafast information transmission and processing as well as ultra-intense energy concentration and extraction. It also holds the key to unlock new extraordinary fundamental physical effects. Traditionally, spatiotemporal light pulses are always treated as spatiotemporally separable wave packet as solution of the Maxwell's equations. In the past decade, however, more generalized forms of spatiotemporally nonseparable solution started to emerge with growing importance for their striking physical effects. This roadmap intends to highlight the recent advances in the creation and control of increasingly complex spatiotemporally sculptured pulses, from spatiotemporally separable to complex nonseparable states, with diverse geometric and topological structures, presenting a bird's eye viewpoint on the zoology of spatiotemporal light fields and the outlook of future trends and open challenges.Comment: This is the version of the article before peer review or editing, as submitted by an author to 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

High Energy Astronomy Observatory, Mission C, Phase A. Volume 2: Preliminary analyses and conceptual design

An analysis and conceptual design of a baseline mission and spacecraft are presented. Aspects of the HEAO-C discussed include: baseline experiments with X-ray observations of space, analysis of mission requirements, observatory design, structural analysis, thermal control, attitude sensing and control system, communication and data handling, and space shuttle launch and retrieval of HEAO-C

Sliceforms: Deployable structures from interlocking slices

A sliceform is a volumetric, honeycomb-like structure assembled from an array of cross-sectional planar slices that are interlocked via pairs of complementary slots placed along each intersection. If the slices are thin, these slotted intersections function as revolute joints, and the sliceform is foldable if the geometry of the embedded spatial linkage permits it, for example a lattice sliceform (LS) is bi-directionally flat-foldable. This thesis concerns a study of such sliceforms toward the design of novel deployable structures. A sliceform torus, composed of two sets of inclined slices arranged at regular intervals about a central axis of symmetry, has been discovered to exhibit a surprising and intriguing folding action whereby its incomplete form can be collapsed to a flat-folded stack of coplanar slices. On deployment, the assembly expands smoothly about an arc until the slices have rotated to their design inclination, then, without reaching any apparent physical limit, abruptly ‘locks out’. With a full complement of slices, the outermost intersections can be interlocked to complete and rigidify the ring. The torus is an example of a rotational sliceform (RS), and analysis of these structures proceeds by noting that their structural geometry comprises an array of pyramidal cells that is commensurate to a spherical scissor grid. The conditions for flat-foldability are determined by examination of the intrinsic geometry of each cell; the incompatibility of the slices with apparent rigid-folding revealed by assessment of the extrinsic motion of the slices. Investigation of their compliant kinematics reveals the articulation to be a bistable transition admitted by small transverse deflections of the slices. This structural form is generalised by development of a technique for generating sliceforms along a smooth spatial curve – curve sliceforms (CS). Their synthesis is more involved than for an RS, but a range of sliceform ‘tubes’ are generated and manufactured. Each example retains the flat-foldable, deployable characteristic of an RS, despite the apparent intrinsic rigidity of each constituent skew cell. Examination of the small-scale models indicates that deployable motion is achieved via imperfect action of the slots, and a simple model of the articulation of a single cell is constructed to investigate how this proceeds, verifying that motion is kinematically admissible via local deformations

Synthesis and Applications of Electromagnetic Metasurfaces

RÉSUMÉ Les métasurfaces électromagnétiques sont des structures bidimensionnelles d’épaisseur fine par rapport à la longueur d’onde d’opération. Elles sont utilisées pour contrôler la diffusion d’ondes électromagnétiques. De telles structures sont conventionnellement composées d’un arrangement périodique de particules diffusantes, de taille plus petite que la longueur d’onde. Ces particules sont conçues de façon à contrôler l’amplitude, la phase, la polarisation et la direction de propagation des ondes réfléchies et transmises par les métasurfaces, lorsque celles-ci sont illuminées par une onde incidente spécifique. L’idée de contrôler la lumière avec des structures d’épaisseur fine n’est pas nouvelle et existe depuis bien longtemps. Cependant, la compréhension mathématique et physique, ainsi que les capacités technologiques requises pour fabriquer ce genre de structures complexes, particulièrement celles qui réalisent un contrôle avancé du champ électromagnétique, n’ont été essentiellement disponibles que depuis les dix dernières années. En outre, malgré les progrès récents, il y a un manque crucial d’une méthode de synthèse, qui soit à la fois rigoureuse et universelle, et qui permette de traiter n’importe quel type de transformation électromagnétique. Il s’ensuit que l’objectif principal de ce travail est de développer un cadre général de synthèse pour l’implémentation mathématique et pratique de métasurfaces, indépendamment de la transformation électromagnétique prescrite. Cette thèse présente une discussion détaillée de la synthèse mathématique de métasurfaces, qui est basée sur des conditions aux limites rigoureuses s’appliquant à des interfaces d’épaisseur nulle. La procédure de synthèse est un problème inverse qui fournit les susceptibilités des métasurfaces en fonction des transformations électromagnétiques spécifiées. Dans ce travail, nous considérons le cas général de métasurfaces bianisotropes possédant des termes de susceptibilités à la fois tangentiels et normaux. La procédure de synthèse est alors séparée en plusieurs cas particuliers, avec un ordre croissant de complexité, qui sont chacun traités de manière individuelle. En plus de cela, la méthode de synthèse a également été étendue afin de prendre en compte le cas de susceptibilités monoisotrope non-linéaire de second ordre. La synthèse mathématique de métasurfaces est illustrée de manière théorique et numérique avec plusieurs exemples qui incluent notamment le design de rotateurs de polarisation réciproques et non-réciproques, ainsi que des transformateurs d’ondes multiples. Une discussion détaillée sur la théorie fondamentale des métasurfaces réfractives est également proposée. Elle décrit différentes configurations de susceptibilités qui permettent de réaliser une transformation réfractive.----------ABSTRACT An electromagnetic metasurface is a two-dimensional structure that is thin with respect to the considered wavelength of operation and that may be used to control the scattering of electromagnetic waves. Such a structure is conventionally composed of a periodic arrangement of engineered subwavelength scattering particles that enables one to control the amplitude, phase, polarization and direction of propagation of the fields reflected and transmitted by the metasurface, when the latter is illuminated by a specific incident field. While the idea of controlling light with thin surfaces has been around for a very long time, the mathematical and physical understanding as well as the technical capabilities required to realize such complex structures, especially the ones that perform advanced control of the fields, have only been available since the last decade. However, there has been a crucial lack of a rigorous and universal synthesis technique that would apply to any field specification. It follows that the main objective of this work is to provide a general synthesis framework for the mathematical and practical implementation of metasurfaces, irrespectively of the prescribed electromagnetic transformations. The thesis presents an in-depth discussion on the mathematical synthesis of metasurfaces that is based on rigorous zero-thickness sheet transition conditions. The synthesis procedure is an inverse problem that yields the metasurfaces susceptibilities in terms of the fields corresponding to the specified electromagnetic transformations. We are considering the very general case of fully bianisotropic metasurfaces with both tangential and normal susceptibility components. The synthesis procedure is then split into different particular cases, with increasing order of complexity, that are individually addressed. Additionally, the synthesis technique is also extended so as to include the case of monoisotropic second-order nonlinear susceptibilities. The mathematical synthesis of metasurfaces is theoretically and numerically illustrated with several examples, which notably include the design of reciprocal and nonreciprocal polarization rotators and multiple wave transformers. A detailed discussion on the fundamental theory of refractive metasurfaces is proposed and which describes various susceptibility configurations that allow one to achieve wave refraction. For each of these configurations, the power conversion efficiency between the incident and refracted wave is also analyzed from a mathematical and physical perspective. Following the mathematical developments of the synthesis, the practical realization of metasurfaces is then addressed

Skylab Operations Handbook: Orbital Workshop (OWS), Airlock Module (AM), Multiple Docking Adapter (MDA)

The Skylab Program consists of three low-earth-orbit missions of the Orbital Assembly (OA) (figure 1.0-1), extending over.an a-month period. The OA consists of the CSM docked to the Saturn Workshop.(SWS). This handbook describes the systems for three of the four major components of the SWS (OWS, AM, and MDA), and also discusses significant interfaces with the Instrument Unit (IU), ATM, and CSM. The other major component of the SWS, the ATM, is treated separately in its own handbook. The OWS, AM, MDA, ATM Deployment Assembly (ATM-DA), Fixed Airlock Shroud (FAS), Payload Shroud (PS), and IU are addressed throughout this document as individual modules from a structural standpoint only. Although normally considered a part of the launch vehicle, the IU is treated in this document as part of the SWS because of its function in preparing the SWS for orbital operation. Section 1.0 describes vehicle and mission configurations of the Skylab program and provides general descriptions of the various systems. Section 2.0 provides detailed systems data covering system interfaces, functional description, subsystems and major components description, component operation, failure modes, performance and design data, operational limitations and restrictions, and instrumentation, and briefly outlines the experiments. Section 3.0 contains illustrations of all panels and identifies the controls and displays, panels, reference designators, nomenclature, functions, circuit breakers, and power sources. The Table of Contents lists in order of appearance all sections, subsections, major paragraphs, illustrations, and tables and provides their respective page locations. Appendix A defines the abbreviations and acronyms employed throughout this handbook, and Appendix B explains the symbols used. Appendix C is a locator index that references component controls contained in Section 3.0. Appendix D is an alphabetical index of paragraph headings, illustrations, and tables, according to the key word, with applicable page numbers. Additional items of significance to the user have been included in the index. The technical level to which this document is written assumes the reader to have general knowledge of engineering terms and principles

Bibliography of Lewis Research Center technical publications announced in 1984

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1984. All the publications were announced in the 1984 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

An advanced study of an Application Technology Satellite /ATS-4/ mission, volume I, book 2 Final study report, May - Nov. 1966

Application Technology Satellite /ATS/ SPACECRAFT tradeoff and analysis - configuration paraboloid antenna, guidance and control power, spacecraft design, and apogee motor selectio

Design and Analysis of Advanced Photonic Devices for Electromagnetic Transmission and Sensing

In this thesis, we report the investigation of advanced photonic devices for electromagnetic transmission and biochemical sensing in the terahertz and optical regimes. The choice of material for designing a terahertz device is deemed to be one of the most crucial factors. First, we consider materials that are frequently used in making terahertz devices. We experimentally demonstrate the optical, thermal, and chemical properties of various chosen glasses, polymers, and resin to select the optimal material for terahertz. Second, we perform a broad review on terahertz optical fibres—this includes various fibre categories, their guiding mechanisms, fabrication methodologies, possible experimental methodologies, and applications. Third, we analyse and demonstrate the design of various fibre structures for terahertz transmission and sensing, and then perform experiments on a hollow core antiresonant fibre. We demonstrate successful fabrication of an asymmetrical Zeonex fibre using a novel fabrication method. This is carried out by using a tabletop horizontal extruder designed for producing polymer filaments. The fabricated fibre is then experimentally investigated for terahertz transmission and gas sensing. Fourth, we study optical fibre based surface plasmon resonance biosensors for operation in the optical regime. Theoretical studies are undertaken to obtain the best possible sensor in consideration of performance, experimental feasibility, and fabrication. One of the optimized sensors is then fabricated as a possible candidate for possible realworld sensing applications. Finally, we study metasurface planar devices for achieving high sensitivity and quality factor in the terahertz regime. We first demonstrate a tunable graphene metasurface that can achieve multi-band absorption and high refractometric sensing. Later, we demonstrate on an all-dielectric metasurface that reports highest Q-factor in the terahertz regime. We fabricate and experiment on the dielectric metasurface and find good agreement with the simulation.Thesis (Ph.D.) -- University of Adelaide, School of Electrical & Electronic Engineering, 202

Graduate Catalog, 1999-2002, New Jersey Institute of Technology

https://digitalcommons.njit.edu/coursecatalogs/1004/thumbnail.jp