Global ETD Search
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 24 for “"quantum dot lasers"”.
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Semiconductor quantum dot lasers.
Stimulated emission in semiconductor quantum dot (QD) laser structures is demonstrated. Red-emitting, self-assembled QDs of highly strained InAlAs were grown by molecular beam epitaxy on GaAs substrates. Carriers injected electrically from the doped regions of separate confinement heterostructures …
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Optically injected dual state quantum dot lasers
… the excitable pulses seen in optically injected lasers. This thesis investigates the feasibility of optically injected dual state quantum dot lasers as artificial photonic neurons. Photonic waveguides are not as sensitive to centimetre long transmission lines as electronic circuits. This could be …
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Design and fabrication of quantum-dot lasers
Semiconductor lasers using quantum-dots in their active regions have been reported to exhibit significant performance advantages over their bulk semiconductor and quantum-well counterparts namely: low threshold current, high differential gain and highly temperature stable light-current …
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Theory of Tunneling-Injection Quantum Dot Lasers
… tunneling-injection of electrons and holes into quantum dots (QDs) from two separate quantum wells (QWs). The potential of such a tunneling-injection QD laser for temperature-stable and high-power operation is studied under the realistic conditions of out-tunneling leakage of carriers from QDs …
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High power ultra-short pulse Quantum-dot lasers
… novel multi-section laser diodes based on quantum-dot material are designed and investigated which exhibit a number of advantages such as low threshold current density; temperature-insensitivity and suppress carrier diffusion due to discrete nature of density of state of quantum-dots. The …
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Theory of Modulation Response of Semiconductor Quantum Dot Lasers
… theory of modulation response of a semiconductor quantum dot (QD) laser is developed. The effect of the following factors on the modulation bandwidth of a QD laser is studied and the following results are obtained:<br /><br />1) Carrier capture delay from the optical confinement layer into QDs<br …
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Techniques for high-speed direct modulation of quantum dot lasers
… transmitters, directly-modulated semiconductor lasers are widely used in todays fiber optical link systems by taking its advantage of their low cost, compact size and low power consumption. In this work, techniques to improve the high frequency modulation characteristics of semiconductor lasers …
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Theoretical study of performance characteristics of semiconductor quantum dot lasers
… the operating characteristics of a semiconductor quantum dot (QD) laser is studied. Specifically, the following topics are included in the dissertation: 1) Effect of carrier-density-dependent internal loss in the optical confinement layer (OCL) on the characteristic temperature. Internal optical …
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Optical and Electrical Properties of Novel Quantum Dot Lasers and Amplifiers
In the case of the tunneling injection InP QD FP laser, a particular transverse-electric (TE) gain narrowing and transverse-magnetic (TM) gain pinning is measured below threshold. A polarization-dependent photon-mediated carrier redistribution with the coupled rate equation model is proposed to …
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Theoretical Study of Semiconductor Quantum Dot Lasers with Asymmetric Barrier Layers
Small-signal dynamic response of semiconductor quantum dot (QD) lasers with asymmetric barrier layers was studied. Semiconductor lasers are used in many communication systems. Fiber optic communication systems use semiconductor lasers in order to transmit information. DVD and Blu-ray disk players …
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Metalorganic Chemical Vapor Deposition of High-Performance GaAs-Based Quantum-Dot Lasers
… (MOCVD) neuartiger GaAs-basierter Halbleiter-Laserstrukturen mit selbstorganisierten InGaAs/GaAs Stranski-Krastanow-Quantenpunkten (QPen) als aktivem Medium hinsichtlich der Lasereigenschaften erzielt. Die dreidimensionale QP-Morphologie führt zu einer Aufrauhung dünner Bedeckungsschichten auf …
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Theory of Operating Characteristics of Quantum Dot Lasers with Asymmetric Barrier Layers
In this work, the operating characteristics of quantum dot (QD) lasers with asymmetric barrier layers (ABLs) are studied. Several different cases are examined, in particular: 1) Effect of excited states on static and dynamic operating characteristics Within QDs, in addition to the lasing ground …
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Structural and Opto-Electronic Properties of GaAs and InP Based Quantum Dot Lasers
… properties of state-of-the-art GaAs and InP quantum dot (QD) lasers is reported. <br/> <br/>A high resolution structural analysis allows a size anisotropy of commercial GaAs based QDs to be determined. A model to simulate the shape of the density of states is then developed which accurately …
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Monolithic 1.3 μm InAs/GaAs Quantum Dot Lasers on Silicon: Simulation and Experiment
1.3 μm quantum dot (QD) lasers epitaxially grown on silicon have attracted great interest as light source for silicon photonics and other optical communication applications. This work focuses on improving the understanding of the physical mechanisms limiting the performance of these devices, and on …
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Mid-infrared antimonide based type II quantum dot lasers for use in gas sensing
Type II InSb/InAs quantum dots (QDs) emitting in the 3-4 µm range are promising candidate as the gain medium for semiconductor laser diodes. The molecular beam epitaxy (MBE) growth of the QDs on GaAs and InP substrates can largely cut down the costs for future devices and massively broaden its …
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High-speed modulation of semiconductor lasers and properties of silver-coated quantum-dot lasers
… a great deal of research interest in plasmonic lasers, in which the optical field is confined by a metal waveguide instead of the more traditional dielectric waveguide. These devices show great promise because of their strong optical confinement and scalability below the diffraction limit. Both …
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Operating regimes of injection-locked quantum-dot lasers and applications in high-speed optical sampling
Abstract currently unavailable. Restricted access until 31.08.2024. Please refer to PDF.
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Theoretical and Experimental Investigation of the Nonlinear Dynamical Trends of Passively Mode-Locked Quantum Dot Lasers
In recent years, passively mode-locked quantum dot lasers have shown great promise as compact, efficient and reliable pulsed sources of light for a range of precision and high performance applications, such as high bit-rate optical communications, diverse waveform generation, metrology, and clock …
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Effect of Out-Tunneling Leakage and Electron-Hole Asymmetry on Modulation Response of Semiconductor Double Tunneling-Injection Quantum Dot Lasers
… Bandwidth in Double Tunneling Injection Quantum Dot Lasers To purely focus on this effect, the conditions of instantaneous carrier exchange between the OCL and QW (on each side of the structure) and tunneling injection into QDs are assumed and closed-form analytical expressions for …
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