Study and characterization of a new optical passive phase shifter

Phase shifters are necessary in order to design optical components for fibr e optics networks such as mode selectors, frequency filters and some intert erometric devices. We propose a new type of passive phase shifters, which w e have called delay lines. These are based on modifying the waveguide width s instead of modifying the length of the waveguides, as was the usual metho d so far. In this paper we discuss in detail the delay difference between t he two planar waveguides that compose our shifter and present simple closed equations to design it. We also carry out a comparative study between our delay lines and the traditional bent shifters. (C) 2000 Elsevier Science B. V. All rights reserved.