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Showing 1 to 20 of 44 for “"Distributed Bragg Reflector"”.
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Surface -Etched Distributed Bragg Reflector Lasers in Photonic Integrated Circuits
A high-power DBR laser array is also presented for use in spectral beam combining systems. The laser structure for this application is engineered for high-power applications. The engineering of the lateral optical guiding structure as well as the surface-etched grating is discussed.
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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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Swept-Frequency Sampled Grating Distributed Bragg Reflector Lasers Optimized for Optical Coherence Tomography Applications
… sources at a low cost. The sampled grating distributed Bragg reflector (SG-DBR) laser provides wide wavelength tuning range while exhibiting a wavelength switching speed that is among the fastest currently available. The SG-DBR laser is used to generate linear frequency ramps with high …
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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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Investigation of porous alumina as a self-assembled diffractive element to facilitate light trapping in thin film silicon solar cells
… photonic crystal, which incorporates a backside distributed Bragg reflector with a diffraction grating for large-angle diffraction. This study develops a simple and cost-effective fabrication method of using porous alumina as a self-assembled textured photonic crystal. Porous alumina is an …
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Design and fabrication of one-dimensional and two-dimensional photonic bandgap devices
… and in the realization of a wide-bandwidth distributed Bragg reflector ...
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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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Vertical -Cavity Surface -Emitting Lasers Operating in Photonic Crystal Waveguide Defect Modes
… array of etched circular holes in the top distributed Bragg reflector of a vertical cavity surface-emitting laser to achieve single mode operation with a simple fabrication process is carried out. A theoretical analysis of photonic crystals is conducted to design devices, and the accuracy …
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Red emitting photonic devices using InGaP/InGaAlP material system
… consist of a quantum well active region and a distributed bragg reflector at the bottom to reduce loss of emitted light into the substrate. The first device emits at a wavelength of 650 nm and is intended to create a photonic crystal light emitting diode (PCLED). PCLEDs have been demonstrated …
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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 manipulation of helium(2(3)S) atoms with a diode laser
… an InGaAs/GaAs strained multiquantum well with a distributed Bragg reflector to insure single longitudinal mode operation. The laser has been frequency stabilized to less than 1 MHz/hr drift. The helium metastable atom beam is produced by electron impact and the polarization is measured using a …
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Quantum dot polymer composite materials for light management in optoelectronic devices
… distances in the waveguide. Furthermore, a distributed Bragg reflector dramatically mitigates the negative impact of scattering in the waveguide, allowing efficient photon collection and concentration ratio. White-light LED is achieved by using a phosphor material to convert monochromatic …
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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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Block copolymer photonic crystals : towards self-assembled active optical elements
… driven lasing and stimulus responsive tunable reflectors. In pursuing these primary objectives, control of thin film microdomain orientation and novel three-dimensional (3D) optical characterization of block copolymer photonic crystals have been also achieved, both of which can greatly help …
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Point-Spread Function Assessment of SG-DBR Based Swept Source for OCT Imaging
… coherent laser sources. Sampled grating distributed Bragg reflector (SG-DBR) lasers are proven in telecom applications and are expected to fulfill the requirements for SS-OCT at a significantly lower cost than alternative solutions.</p> <p>Constructed entirely on a semiconductor …
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Automated SG-DBR Tunable Laser Calibration Optimized for Optical Coherence Tomography Applications
… waveforms sent to the input of a Sampled Grating-Distributed Bragg Reflector (SG-DBR) laser. Three mirrors control the wavelength, while an internal semiconductor optical amplifier controls the laser output power. In dealing with this complicated tuning mechanism, a manual sweep calibration is too …
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Vertical Cavity Surface-Emitting Lasers Operating With Multiple Photonic Crystal Defect Cavities
… (PhC) pattern with a defect, etched into the top distributed Bragg reflector, to define a defect cavity in a VCSEL. This dissertation investigates the operation of PhC VCSELs that have multiple defect cavities to form arrays of vertically emitting lasers. A major achievement of this work is …
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Rare-earth doped aluminum oxide lasers for silicon photonics
… bandwidth. Following the material development, distributed Bragg reflector lasers were designed and fabricated in a CMOS foundry. The laser cavity was created by introducing gratings on either side of a Si3N4 waveguide. Er3+:Al2O3 was deposited in SiO2 trenches on top of the Si3N4 layer, …
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Integrated erbium lasers in silicon photonics
… the erbium gain spectrum is obtained with both a distributed Bragg reflector and a distributed feedback structure. We demonstrate power scaling with output power greater than 75 mW and obtain an ultra-narrow linewidth of 5.3 t 0.3 kHz. We investigate the influence of gain film thickness uniformity …
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Development of high speed vertical cavity surface-emitting semiconductor diode laser and transistor laser
… resistance, a VCTL with AlGaAs and dielectric distributed Bragg reflector (DBR) is fabricated. Because of the mismatch between the cavity design and the quantum well emission, the VCTL is only able to show stimulated emission at low temperatures.
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