We present a detailed investigation of the phase noise characteristics of a harmonically mode-locked erbium doped fiber ring laser. Rms timing jitter < I ps has been measured for a 2 GHz optical pulse train with no active stabilization of the laser.
IntroductionThe generation and transmission of microwave and millimeter-wave signals using optical techniques is required for applications as diverse as optical fiber microcellular and picocellular communication systems, and optical phased arrays. Pulsed semiconductor lasers in conjunction with broad bandwidth photodetectors are capable of generating the very high frequency signals required for such applications. Techniques such as passive mode-locking, active mode-locking, hybrid mode-locking and gain-switching have been used to demonstrate GHz pulse repetition rates with corresponding rf spectra containing frequency components greater than 40 GHz [l-31.