Quantum Dot Laser Tolerance to Optical Feedback

Enhancement of the Modulation Dynamics of an Optically Injection-Locked Semiconductor Laser Using Gain Lever

“…Calculations are done with K = 0, 1, 3.5, 8, while the corresponding values of the normalized detuning are set to ∆f f R = 0, -0.6, 1.7, 4.0. Note that this value of γ b is closer to that reported for QD lasers under normal operation, but as gain compression is not taken into account in the present model the value of f R may be slightly overestimated [35]- [37]. This case better reveals the evolution of the transfer function of an optically injectionlocked laser : as the injection becomes stronger, while the resonance is pushed towards higher frequencies due to the red-shift of the slave laser, a dip appears at lower frequencies and limits the -3 dB bandwidth.…”

Regimes of external optical feedback in 5.6 μm distributed feedback mid-infrared quantum cascade lasers

“…23 A slight external perturbation such as external optical feedback is usually enough to induce sustained pulsating intensities. [24][25][26] As such, the rules of the destabilization and hence the transition towards chaotic operation, which is usually driven through undamped relaxation oscillations in interband semiconductor lasers, certainly follow different routes in case of QCLs. Although no coherence collapse operation has been reported in recent experiments conducted on both THz and mid infrared QCLs, 14 it is important to stress that the onset of the coherence collapse is also strongly dependent on the DFB laser structure, as already pointed out for near infrared emitters.…”

Tuning the external optical feedback-sensitivity of a passively mode-locked quantum dot laser

“…Detailed theoretical and experimental studies have previously found that the sensitivity of quantum dot semiconductor lasers to external optical feedback is strongly influenced by the extent to which the relaxation oscillations (ROs) of the output are damped. [17][18][19] In this connection, it may be noted that the influence of Spectral Hole Burning (SHB) on the dynamical response of semiconductor lasers has received considerable attention over the years. Generally speaking, SHB is known to increase the damping rate of ROs, so that a stronger SHB-effect will lead to strongly damped ROs.…”