With the advent of lasers, numerous applications of it such as optical
information processing, holography, and optical communication have
evolved. These applications have made the study of optics essential for
scientists and engineers. The present volume, intended for senior under-
graduate and first-year graduate students, introduces basic concepts
neces- sary for an understanding of many of these applications. The book
has grown out of lectures given at the Master's level to students of
applied optics at the Indian Institute of Technology, New Delhi.
Chapters 1-3 deal with geometrical optics, where we develop the theory
behind the tracing of rays and calculation of aberrations. The formulas
for aberrations are derived from first principles. We use the method in-
volving Luneburg's treatment starting from Hamilton's equations since we
believe that this method is easy to understand. Chapters 4--8 discuss
the more important aspects of contemporary physical optics, namely,
diffraction, coherence, Fourier optics, and holog- raphy. The basis for
discussion is the scalar wave equation. A number of applications of
spatial frequency filtering and holography are also discussed. With the
availability of high-power laser beams, a large number of nonlinear
optical phenomena have been studied. Of the various nonlinear phenomena,
the self-focusing (or defocusing) of light beams due to the nonlinear
dependence of the dielectric constant on intensity has received
considerable attention. In Chapter 9 we discuss in detail the
steady-state self-focusing of light beams.