Analysis of the phase-locking dynamics of a III-V-on-silicon frequency comb laser

TL;DR

This paper characterizes the phase-locking dynamics of a hybrid III-V-on-silicon frequency comb laser, identifying regimes of near-transform-limited operation and analyzing the effects of bias voltages on mode-locking stability.

Contribution

It provides a detailed experimental analysis of phase dynamics and introduces a stepped-heterodyne measurement technique for characterizing hybrid mode-locked lasers.

Findings

Identification of near-transform-limited operation regimes

Assessment of mode-locking degradation with bias voltage changes

Demonstration of transform-limited pulses in hybrid mode-locking

Abstract

We present the detailed characterization of the phase dynamics of a telecom hybrid III-V-on-silicon passively mode-locked laser with a ring cavity. We explore the various regimes of operation as a function of gain current and saturable absorber bias voltage. We use a stepped-heterodyne measurement to quantify the spectral chirp and reconstruct the pulse envelop. With this technique we are able to identify regimes of near-transform-limited operation and we assess the degradation of mode-locking in the comb phase relationship when saturable absorber bias voltage is changed. Finally, we present a preliminary study of the phase-locking in hybrid mode-locked operation and demonstrate transform-limited pulses.