Mesoscopic spatiotemporal theory for quantum-dot lasers

Dynamic Spatiotemporal Speed Control of Ultrashort Pulses in Quantum-Dot SOAs

“…Our computational modelling of pulse propagation in QD lasers is based on a mesoscopic theoretical description [7] (see appendix). The propagation of an optical light pulse (in the model realized via the boundary conditions of the light fields at the facets) induces highly nonequilibrium distributions in the charge carrier ensemble populating the dots.…”

“…Due to the specific physical properties of the active medium (e.g., discrete energy levels, high gain, low threshold current, low alpha factor [5] and high-speed modulation [6]) QD based semiconductor optical amplifiers (SOAs) represent promising systems for novel optoelectronic components in data storage and telecommunication. The simulations are based on spatially resolved QD Maxwell-Bloch equations [7] that take into account spatiotemporal light propagation in the waveguiding structure, the spatialdependence and microscopic coupling between light and carriers as well as dynamic excitation and relaxation of the charge carrier plasma via carrier-carrier and carrier-phonon scattering. Our numerical results provide a spatiotemporally resolved analysis of gain and index dynamics responsible for the dynamic shaping of the propagating light pulse.…”

New Approach to Ultra-Fast All-Optical Signal Processing Based on Quantum Dot Devices

“…For the pulse propagation analysis, we replace the variables (z, t) with the retarded frame variables z, τ = t ∓ z/v g . For optical pulses with a duration T 10ps the optical radiation of the pulse is filling the entire active region of a QD SOA of the length L 1mm and the propagation effects can be neglected Gehrig (2002). Hence, in our case the photon densities…”

“…The time-dependent variations of the carrier distributions in the QDs and WL result in the strong phase changes (12) during the light propagation in the QD SOA Gehrig (2002). System of equations (6)- (8) with the average pump and signal photon densities (14) and phases (15) constitutes a complete set of equations describing XGM and XPM in QD SOA related by the LEF α as it is seen from equations (11), (12) and (15).…”

Theory and simulation of ultrafast carrier dynamics and nonlinear pulse propagation in quantum dot semiconductor optical amplifiers

“…We numerically investigate the propagation of an ultra-fast light pulse in the active area of a quantum dot semiconductor optical amplifier (QD-SOA). Our model is based on the theory presented in [1]. In this model the occupation probability of each bound quantum dot (QD) state (refering to electrons and holes) and the corresponding interband polarization is calculated using QD-Bloch equations.…”