Abstract: | We propose an interferometer‐type multistate optical switch and an interferometer‐type digital performance switch using a fiber Bragg grating (FBG) and the phase reversal effect. The effect is a reversing phenomenon of optical phase difference between the reflected and transmitted light from an FBG on a reflectivity spectrum dip between the main reflection band and first sideband. By combining this effect and reflectivity change, the multistate switch including only a single FBG can perform as a four‐state switch. In this paper we describe the principle of the phase reversal effect and some novel optical switch structures, and also the results of experimental examination. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(3): 38–48, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10136 |