Stabilization of subharmonic all-optical clock recovery suing mode-locked laser diodes through a cascading two-stage configuration

摘要

We describe a novel two-stage all-optical subharmonic clock recovery using mode-locked laser diodes. The method we used to improve the stability of all-optical subharmonic clock recovery is based on the injection-synchronization of the MLLD. The first stage is for optical clock extraction at the same frequency as that of the injected optical data, and second stage is the periodic optical pulse injection into a mode-locked diode laser generating a subharmonic frequency. The advantage of the present two-stage scheme is that it enables the expansion of frequency detuning range and the low relative intensity noise (RIN) value for the extracted subharmonic optical clock pulses. This clock recovery scheme was successfully applied to 40- to 10 Gbps all-optical demultiplexing.