Waves, Solitons and Turbulence in Optical Systems - Abstract
Jaurigue, Lina
High-repetition rate ultra-short light sources are essential for optical data communication and all-optical computing. Promising candidates, particularly for on-chip optical data communication, are semiconductor passively mode-locked lasers. Such devices produce light pulses through the interplay between an absorbing and an amplifying section. Due to the absence of an external reference clock these devices exhibit a relatively large timing jitter, which is undesirable for most applications. Several methods of reducing the timing jitter have been studied. Among others, optical self-feedback has been shown to be effective. However, feedback can give rise to fluctuations in the output of oscillatory systems subject to noise, as the noise can excite frequencies resonant to the feedback cavity. We study how a second feedback cavity can be used to suppress these resonant fluctuations. We do this for a Stuart-Landau oscillator with two feedback terms, as well as for a delay differential equation system describing a passively mode-locked laser subject to dual cavity optical feedback. For resonant feedback we find that both systems exhibit the same general behavior in terms of the suppression of resonant fluctuations as a function of the second feedback delay time. For the mode-locked laser system we find feedback delay time regimes for optimal suppression of resonant fluctuations and optimal timing jitter reduction, and we show that dual cavity feedback can given rise to improved long term timing jitter reduction as compared with single cavity feedback.