The field of optics has changed greatly in the past dozen years or so. Partly because of the applied or engineering nature of much of modern optics, there is need for a practical text that surveys the entire field. Such a book should not be a classical-optics text, but, rather, it should be strong on principles, applications and instrumentation, on lasers, holography and coherent light. On the other hand, it should concern itself relatively little with such admittedly interesting phenomena as the formation of the rainbow or the precise deter­ mination of the speed of light. My purpose, therefore, has been to write an up-to-date textbook that surveys applied or engineering optics, including lasers and certain other areas that might be called modern optics. I have attempted to treat each topic in sufficient depth to give it considerable engineering value, while keeping it as free of unnecessary mathematical detail as possible. Because I have surveyed applied optics in a very general way (including much more than I would attempt to incorporate into any single college course), this book should be a useful handbook for the practicing physicist or engineer who works from time to time with optics. Any of the material is appropriate to an introductory undergraduate course in optics; the work as a whole will be useful to the graduate student or applied scientist with scant background in optics.