Repetition rate control of optical self‐injected passively mode‐locked quantum‐well lasers: experiment and simulation

Abstract

The pulse repetition rate (RR) tuning and locking range (LR) as well as the pulse train timing stability of passively mode-locked quantum-well (QW) semiconductor lasers (SCLs) subject to single-cavity optical self-feedback (OFB) are investigated experimentally and by simulations. A simple and universal stochastic time-domain model confirms the experimentally observed RR control and LR as well as timing jitter (TJ) improvement in QW SCLs subject to very long OFB cavities with lengths up to 73.1 m. In particular, the model allows predicting control potential and limits of the RR tuning, locking and TJ improvement depending on the choice of OFB delay length for time-delay modelocked semiconductor laser stabilisation experiments.

Dynamic Intermode Beat Frequency Control of an Optical Frequency Comb Single Section Quantum Dot Laser by Dual-Cavity Optical Self-Injection

“…The qualitative and quantitative agreement obtained by the simple stochastic model to the experimental data in Fig. 3 suggests that the IBF of OFC emitted by the quantum dot SML semiconductor laser and the mechanism of IBLW reduction by external time-delay control appears of the same stochastic origin as demonstrated for PML lasers based on quantum dot [43] and quantum well [44] active regions. We find that the OFC stabilization in quantum dot SML lasers relies on the effective interaction of the timing of the intra-cavity laser signal and the time-delayed OSI laser signal in conjunction with a statistical averaging of the independent timing deviations of both.…”

“…where i (N ) is a sequence of random numbers and N denotes an averaging with respect to the index N . The inequality expresses that a sequence of random numbers has a larger variance than two independent sequences of random numbers [42]- [44]. Term (A) represents a free-running OFC laser with coherently locked modes, term (C) a locking of two OFC lasers.…”

“…It can be optimized by laser cavity design or improved by multi-section cavity layout and laser biasing [24]- [27], passive electrical stabilization [28], [29] or by external control including active mode-locking [30]- [33], electrical modulation or hybrid mode-locking [31], [34], single-and dual-mode injection [35], [36] or mutual synchronization [37]. Self-injection by single passive external cavities [2], [4], [17], [20], [38]- [44] allows to effectively control the IBF and IBLW of mode-locked semiconductor lasers in a frequency range depending on the length of the external cavity [44]. Optical self-injection (OSI) however induces time-delay signature sidebands in the radio-frequency (RF) spectrum which on the other hand can be effectively suppressed by dualcavity OSI as suggested experimentally [45], [46] and confirmed theoretically by modeling [46]- [48].…”

External optical self-injection stabilization of an InP generic foundry platform based passively mode-locked ring laser

“…To reproduce and predict the impact of optical self-injection by one or more external cavities a simple stochastic time-domain model has been developed 19,22 and verified for passively and self mode-locked lasers with active regions based on quantum-dots 19,23 and quantum-wells. 24 The model is based on interaction between the backinjected optical pulses and the pulse within the laser cavity. By changing the length of the external self-injection cavity, a sawtooth shaped dependence of the pulse repetition rate in dependence on this length is expected.…”

Quantum dash frequency comb laser stabilisation by optical self‐injection provided by an all‐fibre based delay‐controlled passive external cavity

“…The OSI cavities can be realised as free-space cavities by using beamsplitters and mirrors mounted on movable delay-stages [27,32]. For longer cavity lengths and better integrability also single-mode fibre based OSI cavities have been reported [28,29,31,[33][34][35][36][37]. However, to precisely control the optical delay of the fibre cavity in the ps-range, usually the light is coupled out of the fibre and the delay length change is carried out in a free-space part of the cavity.…”