Semiconductor-based high repetition rate mode-locked lasers for time and frequency based coherent communications and signal processing applications

摘要

Mode-locked laser designs for both time and frequency domain based applications are presented. It is shown that for strictly time domain applications, simple laser cavity designs can produce pulse trains at 10 GHz with sub-5 fs relative timing jitter (1 Hz-100 MHz) using only commercially available components. Frequency stabilized sources maintain low timing jitter while achieving 1MHz maximum frequency deviations for optical spectra consisting of ～200 10 GHz spaced frequencies. Methods of characterizing pulse-to-pulse timing jitter by examining the photodetected spectrum are reviewed. The effects of the phase noise of an rf source used to drive an actively mode-locked laser on the laser's amplitude and timing fluctuations is also discussed.