Abstract

With the increasing number of services, leading to a rapid capacity increase and, in parallel, the need for more reliable and flexible networks, photonic routing is becoming more and more attractive. A number of recent network architectures take advantage of optics by exploiting their full potential and thus wavelength and space switching are considered. Wavelength switching requires elements such as tunable emitters, tunable filters, and wavelength translators. As far as space switches are concerned, most of the recent progress has been in guided- wave switching matrices, using either LiNbO₃ or III–V semi- conductor materials. Although the latter have greater potential, their performances to date have been below those of LiNbO₃ devices. This paper reviews the digital optical switch (DOS), initially demonstrated on LiNbO₃ but now successfully implemented on InP. Compared to other guided-wave switching elements, the DOS has the advantage of combining in a single device polarization independence, large optical bandwidth, and low driving power. The design optimization of the structure and the technological steps needed for the device fabrication will be presented.

© 1994 Optical Society of America