Optical carrier reuse with gain compression and feed-forward semiconductor optical amplifiers

Two techniques using semiconductor optical amplifiers (SOA) for optical carrier regeneration in networks with wavelength reuse were tested. The main objective was to recover an optical carrier by all-optical erasing its amplitude modulation. The first technique employs gain compression of deeply saturated SOAs. The second technique uses the feed-forward approach where the erasing effect is obtained by injecting a current signal with the inverse of the incoming optical pulse shape into the SOA. It was observed that the SOA gain recovery time limits the maximum usable bit rate for both techniques. Theoretical simulation showed good agreement with experimental results.