This book explores the possibility of using azimuthal Walsh filters as an effective tool for manipulating far-field diffraction characteristics near the focal plane of rotationally symmetric imaging systems. It discusses the generation and synthesis of azimuthal Walsh filters, and explores the inherent self-similarity presented in various orders of these filters, classifying them into self-similar groups and sub-groups. Further, it demonstrates that azimuthal Walsh filters possess a unique rotational self-similarity exhibited among adjacent orders. Serving as an atlas of diffraction phenomena with pupil functions represented by azimuthal Walsh filters of different orders, this book describes how orthogonality and self-similarity of these filters could be harnessed to sculpture 2D and 3D light distributions near the focus.

Since the incorporation of scientific approach in tackling problems of optical instrumentation, analysis and design of optical systems constitute a core area of optical engineering. A large number of software with varying level of scope and applicability is currently available to facilitate the task. However, possession of an optical design software, per se, is no guarantee for arriving at correct or optimal solutions. The validity and/or optimality of the solutions depend to a large extent on proper formulation of the problem, which calls for correct application of principles and theories of optical engineering. On a different note, development of proper experimental setups for investigations in the burgeoning field of optics and photonics calls for a good understanding of these principles and theories. With this backdrop in view, this book presents a holistic treatment of topics like paraxial analysis, aberration theory, Hamiltonian optics, ray-optical and wave-optical theories of image formation, Fourier optics, structural design, lens design optimization, global optimization etc. Proper stress is given on exposition of the foundations. The proposed book is designed to provide adequate material for 'self-learning' the subject. For practitioners in related fields, this book is a handy reference. Foundations of Optical System Analysis and Synthesis provides A holistic approach to lens system analysis and design with stress on foundations Basic knowledge of ray and wave optics for tackling problems of instrumental optics Proper explanation of approximations made at different stages Sufficient illustrations for facilitation of understanding Techniques for reducing the role of heuristics and empiricism in optical/lens design A sourcebook on chronological development of related topics across the globe This book is composed as a reference book for graduate students, researchers, faculty, scientists and technologists in R & D centres and industry, in pursuance of their understanding of related topics and concepts during problem solving in the broad areas of optical, electro-optical and photonic system analysis and design.

The book explains the classification of a set of Walsh functions into distinct self-similar groups and subgroups, where the members of each subgroup possess distinct self-similar structures. The observations on self-similarity presented provide valuable clues to tackling the inverse problem of synthesis of phase filters. Self-similarity is observed in the far-field diffraction patterns of the corresponding self-similar filters. Walsh functions form a closed set of orthogonal functions over a prespecified interval, each function taking merely one constant value (either +1 or 1) in each of a finite number of subintervals into which the entire interval is divided. The order of a Walsh function is equal to the number of zero crossings within the interval. Walsh functions are extensively used in communication theory and microwave engineering, as well as in the field of digital signal processing. Walsh filters, derived from the Walsh functions, have opened up new vistas. They take on values, either 0 or phase, corresponding to +1 or -1 of the Walsh function value.