OPTICAL HOMODYNE DETECTION USING AN IMPROVED DECISION DIRECTED PHASE-LOCKED LOOP

Study of an improved decision directed optical phase locked loop (OPLL) for coherent optical detection is presented. It comprises of all the components of a standard OPLL in conjuction with an optical phase modulator. Detail theory, and performance analysis for the proposed loop have been carried out. Results obtained thereby indicate that the tracking performance of the proposed loop improves to a large extent, and hence the laser linewidth requirement can be considerably relaxed for the purpose of synchronous detection.