Dynamical regimes in a monolithic passively mode-locked quantum dot laser

Abstract

Operation regimes of a two section monolithic quantum dot (QD) mode-locked laser are studied experimentally with InGaAs lasers and theoretically, using a model that takes into account carrier exchange between QD ground state and two-dimensional reservoir of a QD-in-a-well structure. It is shown analytically and numerically that, when the absorber section is long enough, the laser exhibits bistability between laser off state and different mode-locking regimes. The Q-switching instability leading to slow modulation of the mode-locked pulse peak intensity is completely eliminated in this case. When, on the contrary, the absorber length is rather short, in addition to usual Q-switched mode-locking, pure Q-switching regimes are predicted theoretically and observed experimentally.

Hybrid Mode Locking in Semiconductor Lasers: Simulations, Analysis, and Experiments

“…These profiles are shown inside the corresponding tongues. Dash-dotted curves in the middle of the locking tongues represent frequency shifts δf P (a) defined by (16). Inset shows the dependence of the pulse repetition frequency f P of the free-running laser on the absorber relaxation rate γ q .…”

“…1(a). Later this model was extended to take into account the carrier exchange between carrier reservoir and discrete levels in quantum dots [9], [15], [16]. In this paper, however, in order to keep our numerical and analytical analysis as simple as possible, we use the original version of the model proposed in [11]- [13].…”

Optically injected mode-locked laser

“…The term ηe iωt represents optical injection with η denoting the injection strength and ω = 2π ν. Here ν = ν − ν 0 measures the detuning of the frequency ν of injected light from [6,[11][12][13][14][15].…”

Modelling of passive mode‐locking in InAs quantum‐dot lasers with tapered gain section

“…Despite the assumptions and approximations introduced, DDE models represent a powerful and computationally efficient approach for the simulation of ML in semiconductor lasers [6,7]. In [5], we proposed a new MS-DDE model and we demonstrated its effectiveness in providing an improved description of QD MLLs with twosection Fabry-Perot cavity.…”

“…In addition non saturable losses are introduced between any two adjacent sections including both internal losses α k int (due to propagation in the k th section) and output coupling losses K k . With respect to standard DDE models [6,7], the above assumptions allow defining a ring laser structure shown in Fig. 1b whose dynamic behaviour is equivalent to the tapered FP MLL shown in Fig.…”