The 1990 International Topical Meeting on Photonic Switching was held April 12-14, 1990, in Kobe, Japan, in conjunction with the 1990 International Meet ing on Optical Computing. It was sponsored by the Institute of Electronics, Information and Communication Engineers in cooperation with the IEEE Lasers and Electro-Optics Society, the Optical Society of America, and the Japan So ciety of Applied Physics. The attendance was in excess of 340 persons, with 18 countries represented - a testimony to the current international interest in photonic switching. This book contains expanded and more detailed versions of most of the papers presented at the topical meeting. With the success of optical fibers there is an increased demand for a switch ing system that can operate directly on the light present in the fibers. The goal is to reduce the total number of optical-to-electrical and electrical-to-optical transformations as far as possible, in addition to exploiting the large spec tral and temporal bandwidth offered by such an optically transparent system.