All-optical coding of mode-locked semiconductor laser pulse trains for high bit rate optical communications

Abstract

We demonstrate an all-optical scheme for coding high frequency mode-locked semiconductor laser pulse trains. The scheme is experimentally demonstrated by optically modulating a high frequency pulse train at 38 GHz generated by a subharmonic synchronous mode-locked semiconductor laser with binary information contained in multiple low bit rate optical data signals (3.8 Gb/s). Synchronization between the two signals is achieved through optical injection into the mode-locked laser while high speed modulation is achieved via a nonlinear optical loop mirror made of dispersion shifted fiber. The coding scheme has advantages over existing passive multiplexing schemes in generating high data rate opt..