Based on more than 30 years of research on differential theories of gratings, this book describes developments in differential theory for applications in spectroscopy, acoustics, X-ray instrumentation, optical communication, information processing, photolithography, high-power lasers, high-precision engineering, and astronomy. Introducing the Fast Fourier Factorization approach to improve the convergence of a truncated series, the book examines multilayers, stacked gratings, crossed gratings, photonic crystals, and isotropic and anisotropic materials; techniques and examples in grating design; and Maxwell equations in a truncated Fourier space.

This book is devoted to the numerous phenomena arising from the interplay between electromagnetic resonances and nonlinear optical interactions. These resonances are associated with surface plasmas or guided waves, excited in nonlinear optical resonators such as prisms or grating couplers. Topics include rigorous theories of diffraction by gratings in nonlinear optics, presented in a form ready for numerical implementations; scattering the matrix description in nonlinear optics leading to the phenomological approach based on the use of poles and zeros and other behaviours.