Modeling and simulations of broad-area edge-emitting semiconductor devices

Abstract

We present a (2 + 1)-dimensional partial differential equation model for spatial-lateral dynamics of edge-emitting broadarea semiconductor devices and several extensions of this model describing different physical effects. MPI-based parallelization of the resulting middle-size numerical problem is implemented and tested on the blade cluster and separate multi-core computers at the Weierstrass Institute in Berlin. It was found that an application of 25-30 parallel processes on all considered platforms guaranteed a nearly optimal performance of the algorithm with a speedup of around 20-25 and an efficiency of 0.7-0.8. It was also shown that simultaneous usage of several in-house available multi-core computers allows for a further increase of the speedup without a significant loss of efficiency. Finally, the importance of the considered problem and efficient numerical simulations of this problem were illustrated via a few examples occurring in real world applications.

Beam-combining scheme of high-power broad-area semiconductor lasers with Lyot-filtered reinjection: modeling, simulations, and experiments

“…The last two factors depend on the excess carrier density and take into account nonlinear gain compression [6] and material gain dispersion. To mimic a heating-induced red-shift of the lasing wavelengths and a corresponding broadening of the far-fields, we assume additional linear bias current I-dependent contributions to the gain peak wavelength and the excess refractive index, δ h n = (c h n + L h n (x))I [4]. The heating-induced lateral profile L h n (x) within the emitter can be approximated by a negative parabola [7] or, even better, by a suitable Lorentzian or supergaussian, but, in general, should be estimated experimentally or precomputed using the heat transport model defined within the transversal cross-section of the BAL [8].…”

“…For more details on the algorithms used to solve the TW model see Refs. [4,10]. In our work, we have simulated l = 4 mm long BALs having 100 µm width of the contact stripe, and operating at about λ 0 = 975 nm wavelength.…”

“…Other parameters werē n s = 3.42,ñ s = 3.915, R −l = 0.95, R 0 = 0.04, whereas the parameters defining gain dispersion, propagation factor β, and carrier rate equations are similar to those used in Refs. [4,6]. For F = 0, the model above allows simulating the dynamics in solitary BA laser.…”

“…Our theoretical analysis is based on numerical simulations of the compound BAL+EC system, where dynamics of BALs is governed by the 2 (space) + 1 (time) -dimensional traveling wave (TW) model [4], whereas field propagation within the EC and its reinjection into the BALs are defined by an efficient model derived below in this work. Up to our knowledge, modeling and simulation of such BAL+EC configuration are made for the first time in this paper.…”

Chirped photonic crystal for spatially filtered optical feedback to a broad-area laser

“…Our main task here is to efficiently simulate the propagation of the optical field in the EC with an optimized PhC, and to properly calculate the field dynamics in the composite devices of BASL+EC. To simulate the dynamics of BALs we use the 2 (space) + 1 (time) dimensional traveling wave (TW) model [16] and the related parallel solver BALaser [17] developed at the Weierstrass Institute in Berlin and executed on the multicore compute servers there [18]. According to the TW model, the spatiotemporal evolution of the slowly varying complex amplitudes of two waves E + (z, x, t) and E − (z, x, t), counterpropagating along the longitudinal axis (z-coordinate), is governed by the following TW equations on the interval Here, v g , k 0 = 2π/λ 0 , n, and F ± sp are the group velocity of light, the free-space central wavenumber for an employed wavelength λ 0 = 975 nm, the reference refractive index, and the Langevin noise term, respectively.…”