Abstract

All-optical switching devices operating at 1.55 µm wavelength are necessary components for future high-speed optical telecommunication systems. SOA-based symmetric Mach-Zehnder switches can provide fast switching speeds and high on-off contrast, but they require hybrid passive-active integration technology, ¹ and the unswitched data stream cannot be recovered after passing through the device.² Other proposed switching schemes make use of the purely passive ultrafast nonlinear optical effects in Mach-Zehn-der interferometers, distributed Bragg gratings or nonlinear directional couplers.^3–5 These devices, however, suffer from low on-off contrast ratios due to the generally weak material nonlinearity in the transparent regime, which translates into high switching energy requirements. By using resonance to enhance the nonlinear effect in a micro-cavity, the on-off contrast and switching power can be improved without overly compromising the switching speed. In this paper we demonstrate enhanced nonlinear all-optical switching using semiconductor microring resonators. The high quality factors and picosecond lifetimes of these microring devices allow low-power, high-contrast and high-speed switching to be achieved.

© 2002 Optical Society of America