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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 17 of 17 for “"Distributed Bragg reflector (DBR)"”.
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Fabrication and measurements of surface-etched grating distributed Bragg reflector laser
… of the laser gain is relatively broad, so a distributed Bragg reflector (DBR) laser is used to make a narrow linewidth laser. The thesis discusses semiconductor lasers that use surface-etched DBR along with the physics of both the semiconductor and the DBR laser. The topics addressed are the …
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Technological assessment of light-trapping technology for thin-film Si solar cell
The proposed light trapping technology of Distributed Bragg Reflector (DBR) with Diffraction Grating (DG) and Anti-Reflection Coating (ARC) for thin film Si solar cell was analyzed from the technology, market, and implementation perspectives. Two applications were investigated. For monocrystalline …
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Narrow frequency-band laser with optical feedback
… laser with optical feedback. We use a distributed Bragg reflector (DBR) laser diode centered at the cesium D₂ transition wavelength, [gamma] = 852 nm. The linewidth of this diode is reduced by several orders of magnitude by means of optical feedback from an external cavity. The system …
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Optical loss and high-speed modulation of vertical-cavity surface-emitting lasers
… varying the impurity doping concentration in the distributed Bragg reflector (DBR) mirrors of the VCSEL on its maximum power, current threshold, and slope efficiency are examined. By optimizing the amount of impurity doping distributed in the mirrors, improved performance of VCSEL can be …
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Development of high speed vertical cavity surface-emitting semiconductor diode laser and transistor laser
… transmission at 40 Gb/s. With an advanced DBR design for parasitic reduction as well as better thermal conduction and a short 0.5-λ cavity with five quantum wells, an 850 nm VCSEL is able to demonstrate 57 Gb/s error-free transmission at 25 °C and 50 Gb/s error-free transmission at 85 °C. …
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High efficiency thin film silicon solar cells with novel light trapping : principle, design and processing
… the textured photonic crystal (TPC) backside reflector, which can enhance path length by at least several hundred times the film thickness for sufficient absorption. Physical principles and design optimization of TPC are discussed in detail. Thin film Si solar cells integrated with the new …
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Compact Femtosecond Lasers for Multiphoton Imaging
… performance. In contrast, recently introduced Distributed Bragg Reflector (DBR) free technology helps to address these challenges. The second part of this thesis describes the development of 1µm DBR free VECSEL - Membrane External Cavity Surface Emitting Laser (MECSEL), that demonstrated the …
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Wide stripe single and dual wavelength mode semiconductor diode lasers
… wavelength, external gratings such as volume Bragg gratings have been used. These external gratings not only significantly drive up the cost of such integrated systems but also have their drawbacks in that they are very sensitive to mechanical vibrations. This work has focused on the use of an …
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Photosensitivity and Photodarkening of UV-induced Phosphate Glass Fiber Bragg Gratings and Application in Short Fiber Lasers
… the integration of UV-written intra-core fiber Bragg gratings (FBGs) into the fiber laser cavity. The research presented in this thesis is focused on the investigation of photosensitivity of UV-written Bragg gratings in phosphate glass fibers and their application in direct-written short …
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Optical pulse distortion and manipulation through polarization effects and chromatic dispersion
… availability of ultra-long length chirped fiber Bragg gratings (FBG). Their enormous chromatic dispersion enables methods of improving current techniques in sensing and high speed optical sampling. In one experiment, we modulate the frequency of a standard distributed Bragg reflector (DBR) laser, …
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Design and Fabrication of Long -Wavelength Vertical -Cavity Surface -Emitting Lasers Using Wafer Bonding Technologies
… disadvantages associated with the GaInAsP/InP distributed Bragg reflector (DBR) and the fabrication complexity of direct wafer bonding. In this work, a novel VCSEL fabrication method facilitated with new wafer bonding techniques has been developed to overcome these limitations. This process …
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Micro-assembly of integrated photonic devices using a high accuracy transfer printing process
… 3D stacked membrane devices, a 100 µm2 SOI distributed Bragg reflector (DBR) is produced taking advantage of high lateral and rotation placement accuracy. The structure exhibits a visible wavelength reflectance band in agreement with theoretical simulations.The micro-assembly of hybrid …
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Integrated chirped Bragg gratings for dispersion control
… device for this purpose. A monolithic chirped Bragg grating is presented with dispersion and bandwidth characteristics coinciding with the previously mentioned regimes. The device, based on a deeply etched tapered waveguide design, may be fabricated fully post-growth, lending it a significant …
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Thin-film silicon solar cells : photonic design, process and fundamentals
… combines a dielectric grating layer and a distributed Bragg reflector (DBR) for effcient light scattering and reflection, increasing light path length in the thin-film cell. We have understood the operation principles for this design by using photonic band theories and electromagnetic wave …
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Materials science and design for germanium monolithic light source on silicon
… we designed an external cavity Ge laser using distributed Bragg reflector (DBR) gratings on Si waveguides. A detailed discussion on the cross section design was presented to mitigate the internal optical loss from claddings and metal layers and to improve the current injection uniformity across …
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Size and reflectivity dependent optical loss in oxide-confined vertical-cavity surface-emitting lasers
Made available in DSpace on 2017-08-10T20:33:30Z (GMT). No. of bitstreams: 2 LAKOMY-THESIS-2017.pdf: 958914 bytes, checksum: 4bfff61cb428f89b6c2d81ea490c1d54 (MD5) LICENSE.txt: 4213 bytes, checksum: c559050e8766c9fd328f1cde81a9d514 (MD5) Previous issue date: 2017-04-28
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Design and characterization of semiconductor laser structures for hydrogen sensing applications
As gas prices continue to rise and fossil fuels pollute our environment, various alternative fuel sources are being actively pursued. Hydrogen shows considerable promise due to its virtually unlimited supply, energy conversion efficiency, and potentially neutral impact on the environment. However, …