Abstract

A novel family of optical time-division-multiplexed (TDM) switching architectures formed from 2×2 crosspoints and fiber delay lines has recently been reported.¹ Interchannel cross talk in these architectures introduces not only symbol interference but also, as is shown in this paper, significant amounts of noise. In what follows we assume that this cross talk arises principally from the imperfect isolation of the crosspoint outputs. On detection, the cross-talk components mix with the message-carrying signal to produce a photocurrent corrupted by a complex (summed) series of terms. This may be understood by first considering a simple network comprising a single directional-coupler switch fed by cw inputs (Fig. 1). The optical power at the output to which waveform 1 is routed is

© 1994 Optical Society of America