During the last forty years the science of Fiber Optics as well as its technological applications have seen a phenomenal progress so much so that, in recent years, theory and laboratory courses on various aspects of Fiber Optics have been introduced at the undergraduate and postgraduate curricula by many educational institutions - both in basic science as well as in engineering. The present book describes in detail a large number of experiments to characterize an optical fiber, which should help in elucidating its underlying physics for applications in telecommunications and sensor systems. The first edition of the book was well received by students and the academic community. This extensively revised edition would be of greater benefit to students and faculty asociated with a laboratory course on fiber optics.