Delay-induced dynamics and jitter reduction of passively mode-locked semiconductor lasers subject to optical feedback

Abstract

We study a passively mode-locked semiconductor ring laser subject to optical feedback from an external mirror. Using a delay differential equation model for the mode-locked laser, we are able to systematically investigate the resonance effects of the inter-spike interval time of the laser and the roundtrip time of the light in the external cavity (delay time) for intermediate and long delay times. We observe synchronization plateaus following the ordering of the well-known Farey sequence. Our results show that in agreement with the experimental results a reduction of the timing jitter is possible if the delay time is chosen close to an integer multiple of the inter-spike interval time of the laser without external feedback. Outside the main resonant regimes the timing jitter is drastically increased by the feedback.

Emergence of resonant mode-locking via delayed feedback in quantum dot semiconductor lasers

“…and is a generalization of the field equation in [28,29]. E (t) is the normalized complex amplitude of the electric field, while t is the time normalized by the short cavity round-trip time.…”

Intensified antibunching via feedback-induced quantum interference

“…This has been exploited to control laser systems [12]. A more recent proposal uses feedback as a mechanism to reduce the jitter in pulsed lasers or the optoelectronic control of the device based on a classical series of measurements [13,14]. Other possible applications include optomechanical setups [15].…”

Passively mode-locked lasers subject to optical feedback: The role of amplitude-phase coupling

“…It has been shown experimentally that optical feedback can reduce the timing jitter [1], [2]. Theoretical studies have been carried out to gain an understanding of the influence the optical feedback has on the laser dynamics [3], [4]. However a detailed study on the influence of the amplitude-phase coupling on the ML laser subject to optical feedback was still lacking.…”

“…This is important, as the the amplitude-phase coupling greatly influences the dynamics of the free running laser and thus understanding this effect is crucial to predict stable dynamic regimes and to explain experimentally results. We therefore use the delay differential equation (DDE) model introduced in [5], and extended to include optical feedback [3], to investigate the effect of optical feedback on the dynamics of a passively ML laser, focusing on the impact of amplitude-phase coupling (α-factor).…”