All-optical byte recognition for 40-Gb/s phase-shift-keyed transmission using a planar-lightwave-circuit passive correlator

We demonstrate all-optical recognition of a byte pattern embedded in phase-shift-keyed data streaming at 40 Gb/s. We use matched filtering to generate an autocorrelation pulse indicating the pattern matching. 

Matched filtering is implemented using a reconfigurable silica planar-lightwave-circuit optical delay- line filter. We show excellent discrimination against spurious patterns consistent with the theoretical predictions.