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TY - THES AU - Holly, Carlo TI - Modeling of the lateral emission characteristics of high-power edge-emitting semiconductor lasers; 1. Auflage PB - RWTH Aachen University VL - Dissertation CY - Düren M1 - RWTH-2019-08745 SN - 978-3-8440-6923-5 T2 - Lasertechnik SP - 263 Seiten : Illustrationen, Diagramme PY - 2019 N1 - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University N1 - Dissertation, RWTH Aachen University, 2019 AB - In this work, numerical methods for the simulation of broad-area edge-emitting semicon- ductor lasers are presented. Frequency-domain and time-domain models are employed to predict the propagation of the filamented optical field in the semiconductor laser and determine emission characteristics including near-field and far-field profiles, beam width, divergence angle, and power over current. The models utilize wave-optical beam propagation and account for the interaction of the optical field with the spatial (and temporal) varying carrier and temperature distributions inside the semiconductor laser cavity. Once calibrated, the frequency-domain model is utilized to predict emission characteristics of single emitters and laser arrays, which differ in geometrical properties (contact width, cavity length or emitter pitch), epitaxial structure or facet reflectivity. By comparison with experimental data for eight laser designs, which include single- emitter and laser arrays it is demonstrated that the frequency-domain model allows computation of lateral far-field angles and near-field widths as a function of current and thermal state for edge-emitting diode lasers. An opto-mechanical model is derived to compute the degree of polarization for pack- aged single emitter or laser arrays. The mechanical strains, induced by the soldering process, heating of the device during operation and intrinsic lattice mismatch in the device, are considered. The ratio of the shear strain and the lateral (and vertical) strain component(s) determines the degree of polarization. In addition to the frequency-domain model, a time-domain model based on the traveling- wave method is implemented and employed to compute the optical propagation in the QW-plane of an edge-emitting diode laser, including carrier- and temperature-induced refractive index changes. The evolution of the optical field along the cavity is computed iteratively for transverse slices. Alongside with the optical propagation, the carrier diffusion equation and an auxiliary equation for the material polarization are solved. The results obtained with the time-domain model obey similar filamented field profiles like the ones obtained with the frequency-domain model. In summary, the numerical model acts as a digital-twin of the real device and with the simulation tools presented in this work the lateral emission characteristics for edge- emitting laser devices can be predicted to the extent needed to make design decisions. LB - PUB:(DE-HGF)11 ; PUB:(DE-HGF)3 DO - DOI:10.18154/RWTH-2019-08745 UR - https://publications.rwth-aachen.de/record/767328 ER -