Interferometric ultrafast SOA-based optical switches: From devices to applications

All-optical switches are fundamental building blocks for future, high-speed optical networks that utilize optical time division multiplexing (OTDM) te chniques to achieve single channel data rates exceeding 100 Gb/s. Interfero metric optical switches using semiconductor optical amplifier (SOA) non-lin earities perform efficient optical switching with < 500 fJ of control energ y and are approaching optical sampling bandwidths of nearly 1 THz. In this paper, we review work underway at Princeton University to characterize and demonstrate these optical switches as processing elements in practical netw orks and systems. Three interferometric optical switch geometries are prese nted and characterized. We discuss limitations on the minimum temporal widt h of the switching window and prospects for integrating the devices. Using these optical switches as demultiplexers, we demonstrate two 100-Gb/s testb eds for photonic packet switching. In addition to the optical networking ap plications, we have explored simultaneous wavelength conversion and pulse w idth management. We have also designed high bandwidth sampling systems usin g SOA-based optical switches as analog optical sampling gates capable of an alyzing optical waveforms with bandwidths exceeding 100 GHz. We believe the se devices represent a versatile approach to all-optical processing as a va riety of applications can be performed without significantly changing the d evice architecture.