Abstract

Monolithic mode-locked semiconductor lasers are increasingly attractive as very high-repetition rate picosecond optical pulses sources needed for diverse applications including optical sampling, clocking and optical time-division multiplexing in high-speed communication. Conventional passively mode-locked lasers (PMLL) have tight tolerances and high variability of pulse width and jitter relative to the applied gain current and absorber voltage. Recent work has shown [1] that quantum-dot lasers can provide much more reproducible and stable mode-locking, as evidenced by short pulses, narrow RF spectrum and low pulse-to-pulse jitter. Due to the intrinsic phase noise properties of passively mode- locked lasers [2], the study of the RF linewidth can provide a full characterization of the time stability of the source. Here we discuss the application of this method to characterize a promising high repetition rate quantum-dots PMLL and determine the best conditions of operations.

© 2007 IEEE