The propagation of electromagnetic waves in "square-law" media, i.e.,
media characterized by a quadratic spatial variation of the dielectric
constant, has been a favorite subject of investigation in
electromagnetic theory. However, with the recent fabrication of glass
fibers with a quadratic radial variation of the dielectric constant and
the application of such fibers to optical imaging and communications,
this subject has also assumed practical importance. Comparison of
experimental results on propagation, resolu- tion, and pulse distortion
in such inhomogeneous waveguides with theory has put the field on a
sound base and spurred further work. The present book aims at presenting
a unified view of important aspects of our knowledge of inhomogeneous
optical waveguides. A brief discussion of homogeneous dielectric
waveguides is unavoidable, since itforms a basis for the appreciation of
inhomogeneous waveguides. A short course based on some chapters of this
book was offered to graduate students at IIT Delhi and was well
received. We consider that despite the unavoidable mathemati- cal nature
of the present book, the comparison of experimental results with theory
throughout and the description of fabrication technology (Appen- dixes A
and B) should make its appeal universal. The authors are grateful to Dr.
K. Thyagarajan for writing most of Chapter 9 and to their colleagues Dr.
I. C. Goyal, Dr. B. P. Pal, and Dr. A.