The Scattering And Diffraction Of Waves

The scattering of acoustic and electromagnetic waves by periodic sur faces plays a role in many areas of applied physics and engineering. Opti cal diffraction gratings date from the nineteenth century and are still widely used by spectroscopists. More recently, diffraction gratings have been used as coupling devices for optical waveguides. Trains of surface waves on the oceans are natural diffraction gratings which influence the scattering of electromagnetic waves and underwater sound. Similarly, the surface of a crystal acts as a diffraction grating for the scattering of atomic beams. This list of natural and artificial diffraction gratings could easily be extended. The purpose of this monograph is to develop from first principles a theory of the scattering of acoustic and electromagnetic waves by periodic surfaces. In physical terms, the scattering of both time-harmonic and transient fields is analyzed. The corresponding mathematical model leads to the study of boundary value problems for the Helmholtz and d'Alembert wave equations in plane domains bounded by periodic curves. In the formal ism adopted here these problems are intimately related to the spectral analysis of the Laplace operator, acting in a Hilbert space of functions defined in the domain adjacent to the grating.

This book presents a comprehensive tutorial on propagation, diffraction and scattering problems from the basic principles of physical optics. Beginning with the fundamental differential and integral equations for wavefields, the text presents an exhaustive discussion on the extinction theorem as a non-local boundary condition; this has been extensively employed for the rigorous solution of scattering and diffraction problems.There is also an in-depth presentation of the topic of scattering from rough surfaces, in particular the phenomenon of enhanced backscattering, as well as a detailed development of the angular spectrum representation of fields leading to questions on non-diffraction beams. Of key interest in near field optical microscopy and nanooptics, the S-matrix theory based on the angular spectrum for propagating components and the recently discovered properties of the S-matrix for evanescent components of wavefields are considered. In addition, the book deals with the healing effect of phase conjugation on waves, and focuses on some applications concerning the relationship with time reversal.Readers will also find discussions on image recovery from partial information data (phase problems and super-resolution problems), as well as a chapter on the fundamentals of near field optical microscopy techniques, including the hot topic of propagation in negative index media.

This book presents a comprehensive tutorial on propagation, diffraction and scattering problems from the basic principles of physical optics. Beginning with the fundamental differential and integral equations for wavefields, the text presents an exhaustive discussion on the extinction theorem as a non-local boundary condition; this has been extensively employed for the rigorous solution of scattering and diffraction problems. There is also an in-depth presentation of the topic of scattering from rough surfaces, in particular the phenomenon of enhanced backscattering, as well as a detailed development of the angular spectrum representation of fields leading to questions on non-diffraction beams. Of key interest in near field optical microscopy and nanooptics, the S-matrix theory based on the angular spectrum for propagating components and the recently discovered properties of the S-matrix for evanescent components of wavefields are considered. In addition, the book deals with the healing effect of phase conjugation on waves, and focuses on some applications concerning the relationship with time reversal. Readers will also find discussions on image recovery from partial information data (phase problems and super-resolution problems), as well as a chapter on the fundamentals of near field optical microscopy techniques, including the hot topic of propagation in negative index media.

This book is the first complete and comprehensive description of the modern Physical Theory of Diffraction (PTD) based on the concept of elementary edge waves (EEWs). The theory is demonstrated with the example of the diffraction of acoustic and electromagnetic waves at perfectly reflecting objects. The derived analytic expressions clearly explain the physical structure of the scattered field and describe in detail all of the reflected and diffracted rays and beams, as well as the fields in the vicinity of caustics and foci. Shadow radiation, a new fundamental component of the field, is introduced and proven to contain half of the total scattered power.