HIGH-PERFORMANCE HOMODYNE OPTICAL-INJECTION PHASE-LOCK LOOP USING WIDE-LINEWIDTH SEMICONDUCTOR-LASERS

The requirements for narrow linewidth lasers and short loop propagatio n delay limit optical phase-lock loop realizability with semiconductor lasers, Although optical injection locking can provide low-phase-erro r variance, its locking range is Limited by stability considerations, The first experimental results for a new architecture combining both t echniques, the optical injection phase-lock loop (OIPLL), are reported , Phase error variance values as low as 0.006 rad(2) (500 MHz bandwidt h) and locking ranges exceeding 26 GHz are achieved using DFB lasers o f summed linewidth 36 MHz with loop delay of 15 ns and injection ratio less than -30 dB.