A review and tutorial of the fundamental ideas and methods of joint time-frequency distributions is presented. The objective of the field is to describe how the spectral content of a signal changes in time and to develop the physical and mathematical ideas needed to understand what a time-varying spectrum is. The basic gal is to devise a distribution that represents the energy or intensity of a signal simultaneously in time and frequency. Although the basic notions have been developing steadily over the last 40 years, there have recently been significant advances. This review is intended to be understandable to the nonspecialist with emphasis on the diversity of concepts and motivations that have gone into the formation of the field. >

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Time-frequency distributions-a review

An application program interface (API) provides a set of functions for application developers who build Web applications on Microsoft Corporation's .NET™ platform.

Application program interface for network software platform

Diffraction characteristics of general dielectric planar (slab) gratings and surface-relief (corrugated) gratings are reviewed. Applications to laser-beam deflection, guidance, modulation, coupling, filtering, wavefront reconstruction, and distributed feedback in the fields of acoustooptics, integrated optics, holography, and spectral analysis are discussed. An exact formulation of the grating diffraction problem without approximations (rigorous coupled-wave theory developed by the authors) is presented. The method of solution is in terms of state variables and this is presented in detail. Then, using a series of fundamental assumptions, this rigorous theory is shown to reduce to the various existing approximate theories in the appropriate limits. The effects of these fundamental assumptions in the approximate theories are quantified and discussed.

Analysis and applications of optical diffraction by gratings

A theory is developed for dispersion characteristics of spin waves in ferromagnetic films taking into account both the dipole-dipole and the exchange interactions. An arbitrary orientation of the internal bias magnetic field is assumed. The general case of mixing exchange boundary conditions (surface spin pinning conditions) is considered. The simple analytical dispersion equations are obtained using the classical perturbation theory. The modification of the spin wave spectrum due to surface anisotropy (or pinning conditions) is discussed.

https://iopscience.iop.org/article/10.1088/0022-3719/19/35/014/pdf

Theory of dipole-exchange spin wave spectrum for ferromagnetic films with mixed exchange boundary conditions

In order to enable optical systems to operate with a high degree of compactness and reliability it is necessary to combine large number of optical functions in small monolithic structures. A development, somewhat reminiscent of that that took place in Integrated Electronics, is now beginning to take place in optics. The initial challenge in this emerging field, known appropriately as "Integrated Optics", is to demonstrate the possibility of performing basic optical functions such as light generation, coupling, modulation, and guiding in Integrated Optical configurations. The talk will review the main theoretical and experimental developments to date in Integrated Optics. Specific topics to be discussed include: Material considerations, guiding mechanisms, modulation, coupling and mode losses. The fabrication and applications of periodic thin film structures will be discussed.

Integrated optics

Interaction of guided optical waves with microwave magnetostatic waves in yittrium iron garnet thin films has been demonstrated. TM↔TE mode conversion induced by codirectional (and contradirectional) magnetostatic waves was experimentally observed with conversion efficiencies of up to 4%. Theoretical expressions for this interaction are given and compared with observations. The thin‐film geometry demonstrated could make a practical number of optical signal processing devices in the 1–20‐GHz range.

Optical guided‐wave interactions with magnetostatic waves at microwave frequencies

Optical associative, parallel-processing architectures are being developed using a multimodule approach, where a number of smaller, adaptive, associative modules are nonlinearly interconnected and cascaded under the guidance of a variety of organizational principles to structure larger architectures for solving specific problems. A number of novel optical implementations with versatile adaptive learning capabilities are presented for the individual associative modules, including holographic configurations and five specific electrooptic configurations. The practical issues involved in real optical architectures are analyzed, and actual laboratory optical implementations of associative modules based on Hebbian and Widrow-Hoff learning rules are discussed, including successful experimental demonstrations of their operation.

Optical implementations of associative networks with versatile adaptive learning capabilities.

The present invention provides systems and methods to build multi-tiered software applications with a high level of quality and complexity. One specific embodiment of the system includes a design application that guides a designer through a system design process, a generator application that generates and customizes a software solution tailored to the system design and an installation application that modularizes and automates the installation and configuration of the generated software solution.

Methods and systems for automatically generating software applications

Part 1 Introduction to acousto-optics: introduction to acousto-optic interaction theory acousto-optic device technology - basic principles acousto-optic device technology - design. Part 2 Acousto-optic processing fundamentals: the theory of acousto-optic spectrum analyzers acousto-optic tunable filters space-integrating acousto-optic signal processors using surface-acoustic-wave delay lines incoherent-light time-integrating processors coherent time-integration processors. Part 3 Acousto-optic processing implementation: optical information-processing applications of acousto-optics acousto-optic spectrum analyzers acousto-optic wide band correlator system signal delay and compression. Part 4 New directions: image processing applications of acousto-optics low-loss acousto-optic photonic switch.

Acousto-optic signal processing : theory and implementation

An introduction and comparative overview to the state of the art of two-dimensional spatial light modulator technology is provided, touching on the basic operation and performance of most of the more promising electronically- and optically- addressed device technologies. The fundamental functional capabilities and potential applications of these light control devices are also discussed, and some projections are offered on the future directions of spatial light modulator technology.

John N. Lee

Papers

Optical guided‐wave interactions with magnetostatic waves at microwave frequencies

Optical implementations of associative networks with versatile adaptive learning capabilities.

Methods and systems for automatically generating software applications

Acousto-optic signal processing : theory and implementation

The Current Status Of Two-Dimensional Spatial Light Modulator Technology