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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Distributed Bragg reflectors"”.
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Design and fabrication of distributed Bragg reflectors for vertical-cavity surface-emitting lasers
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.
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Advancing optical interconnects: Exploring low-loss 3D photonic waveguides, loop mirrors, and distributed Bragg reflectors
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-08-01
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Reliability and Mode Behavior of AlGaAs-GaAs-InGaAs Quantum Well Heterostructure Lasers
… well heterostructures with oxide-AlxGa1_xAs distributed Bragg reflectors for electromagnetic confinement, showing the full range of reliability after 5+ years of hydrolyzation in ambient conditions of atmospheric water vapor and temperature. The evaluation after 5+ years shows that a quick …
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Design and Characterization of Integrated Photonic Devices Fabricated Using Selective-Area Epitaxy and Distributed Bragg Reflector Surface Gratings
… be provided in integrated photonic devices using distributed Bragg reflectors (DBRs). In this dissertation, ridge-waveguide DBR lasers with first-order surface gratings are investigated. These lasers exhibit low thresholds (6 mA), high slope efficiencies (0.46 W/A), and single-frequency operation …
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Design, growth and optimization of 2-μm InGaSb/AlGaSb quantum well based VECSELs on GaAs/AlGaAs DBRs.
… on InGaSb/AlGaSb quantum wells on AlAsSb/GaSb distributed Bragg reflectors (DBRs), grown latticematched on GaSb substrates. In this work the ability to grow such antimonide VECSEL structures on GaAs substrates is explored. The growth of such III-Sb VECSELs on GaAs substrates is non-trivial due …
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Characterization of OMVPE-grown GaSb-based epilayers using in situ reflectance and ex situ TEM
… in situ reflectance data, and also in designing distributed Bragg reflectors. Phase separation in GaInAsSb was studied using TEM. A wide range of microstructures was observed, from nearly homogeneous to strongly phase separated.
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Development of Nanostructured Light Emitters in Gallium Nitride
… and the integration of InGaN QWs with porous distributed Bragg reflectors (DBRs) is reported, with a corresponding increase in LED efficiency owing to improved light extraction. Porous DBRs are also integrated with InGaN QDs to create prototype optical cavity structures, combined with a …
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Selective mode coupling in microring resonators for single mode semiconductor lasers
… Edge-emitting single mode lasers commonly use distributed feedback structures, or narrowband reflectors such as distributed Bragg reflectors (DBRs) and sampled grating distributed Bragg reflectors (SGDBRs). Compact, narrowband reflectors with high reflectivities are of interest to replace the …
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High-power single-mode vertical-cavity surface-emitting lasers via impurity induced disordering
… for the diffusion of Group III atoms of the distributed Bragg reflectors (DBR) that comprise the VCSEL. In addition, a simple fiber model is used to design the transverse profile of the IID regions to maximize single-mode output power. IID VCSELs are fabricated with special attention given to …
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Microscopy and Spectroscopy of Materials for Blue Single Photon Sources
… of these dots in recently developed mesoporous distributed Bragg reflectors, which boast perfect lattice matching and a facile fabrication method. Microscopy analysis provides insight into the method of etching along dislocation channels, and the changing morphology of the layer stack. …
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Thermal and Optical Simulations of Vertical Cavity Surface Emitting Lasers
… of energy. A novel treatment is applied to model distributed Peltier heat at a heterojunction by use of a Monte Carlo simulation. Peltier heat is found to be a major heat contributor, and it results in a rapid and high temperature rise in the separate confinement heterostructure (SCH) region of …
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Micro- and nano-soft lithography for the fabrication of photonic devices
… lased and the grating structures acted as Distributed Bragg Reflectors (DBRs).Key advantages for the techniques used throughout this thesis are that they allow the patterning of sensitive materials that otherwise would not survive classical lithography due to aggressive chemical treatment …
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Terahertz oscillation and stimulated emission from planar microcavities
… solid state laser compound and high reflectance distributed Bragg reflectors. These lasers combine a very low laser threshold with small beam divergence and good stability. A transfer of the anisotropic design towards an organic VCSEL results in the generation of two perpendicularly polarized …
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Aspects of Photovoltaic Systems: Study and Simulation of Silicon Phthalocyanine Bulk Heterojunction Solar Cells and Monochromatic Photonic Power Converters
… converter was simulated with both metallic and distributed Bragg reflectors at the rear of the device. These reflectors allowed for the thinning of the bottommost junction, which resulted in an increase in efficiency and overall power output of the power converter.
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MOVPE and characterization of GaN-based structures on alternative substrates
… and opto electronic devices. On Si AlN/GaN distributed Bragg reflectors (DBR), InGaN/GaN multiple quantum well (MQW) and AlGaN/GaN HEMT (high electron mobility transistor) were demonstrated. The transistor structures showed high power densities, which were comparable to industrially …
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Tomographic reconstruction and sub-surface imaging of porous nitride semiconductors
… nanostructured nitrides through porous GaN distributed Bragg reflectors (DBRs), highly-reflective and wavelength-selective mirrors for optoelectronic device applications such as next-generation micro light emitting diode (LED) displays. These photonic structures are fabricated through …
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Resonant-cavity-enhanced multispectral infrared photodetectors for monolithic integration on silicon
… As2S3 and sputtered Ge, we design and fabricate distributed Bragg reflectors (DBR) for mid-IR resonant cavities. In our design example of dual waveband RCE photodetectors, peak quantum efficiencies over 80% have been realized in both wavebands (1.55 pm and 3.6 pm) with only 50 nm and 100 nm thick …
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Crecimiento de nitruros del grupo III por epitaxia de haces moleculares para la fabricación de diodos electroluminiscentes en el rango visible-ultravioleta
… abrió las puertas a la fabricación de espejos Bragg (DBR) de InAlN/GaN con ajuste en red centrados a ~ 400 nm y con reflectividades de hasta un 60 % para un total de 10 períodos. El análisis presentado en esta memoria acerca de la incorporación de In en (0001) InAlGaN en función de la …
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GaAs-based quantum well and quantum dot light-emitting diodes and lasers for 1.3 and 1.55 um emission
… temperatura de crecimiento de los reflectores de Bragg que forman la microcavidad, y del aleado de los contactos eléctricos. Se observa que la eficiencia externa, r]ext, y la anchura a media altura de los picos de electroluminiscencia se degradan según disminuye la temperatura de crecimiento de …