Frequency-Division-Multiplex Coherent Optical Switch Experiment with Monolithic Tunable Lasers Covering a 1000-GHz Range

Abstract
Considerable progress has been made in coherent optics for local network applications whereby a star coupler is used to combine various Frequency-Division-Multiplex (FDM) channels from the inbound lines for broadcasting onto each of the outbound lines [1-4]. Many practical challenges in such FDM networks (e.g. synchronization, control of the FDM comb, polarization maintenance etc.) can be minimized when we shrink the entire network inside a "box" so as to build an optical switch capable of cross-connecting many high-speed circuits carried in multi-Gb/s fibers [5], We describe here results of an on-going experiment aimed at exploring the technical feasibility of this approach, and our laboratory demonstration is believed to be the first one done with monolithic tunable lasers covering 1,000 GHz at 700 Mb/s and with a novel tuned, balanced coherent receiver design, yielding a potential switch size as large as 125×125.