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 293 for “"terahertz"”.
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Terahertz wireless communication
The goal of this thesis is to explore Terahertz (THz) wireless communication technology. More specifically the objective is to develop and characterize several THz communication systems and study the effect of atmosphere propagation through fog droplets and dust particles on THz communications. For …
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Broadband terahertz photonics
… as mature semiconductor sources of light in the terahertz range, the frequency range spanning 1 to 10 THz. Though technological development has pushed their operating temperatures up to 200 Kelvin and their power levels up to Watt-level, they have remained unsuitable for many applications as a …
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From high power terahertz quantum cascade lasers to terahertz light amplifiers
The terahertz (THz) frequency range (300 GHz to 10 THz, wavelength 30-1000 [mu]m), despite having many potential applications, is technologically relatively underdeveloped mainly because of the lack of suitable coherent radiation sources when compared with nearby electromagnetic radiation spectrum. …
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Ultrafast Broadband Terahertz Spectroscopy
This dissertation centers on broadband terahertz spectroscopy and is arranged in four main sections. In the first section, we describe terahertz generation from a two-color laser air breakdown plasma. This is modeled with a plasma current that includes plasma density and dispersion in propagation. …
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Terahertz quantum cascade lasers
The development of the terahertz frequency range has long been impeded by the relative dearth of compact, coherent radiation sources of reasonable power. This thesis details the development of quantum cascade lasers (QCLs) that operate in the terahertz with photon energies below the semiconductor …
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High-speed terahertz signal control and read-out for future terahertz communication systems
The realisation of next-generation terahertz (THz) communication systems necessitates fast and efficient THz signal control and readout, enabling the encoding of data streams onto THz-frequency signals and their subsequent decoding. This project aims to design, develop, and demonstrate THz …
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The generation of high field terahertz radiation and its application in terahertz nonlinear spectroscopy
In this thesis research, I implemented a terahertz generation scheme that enables high-field near-single-cycle terahertz (THz) pulse generation via optical rectification in a LiNbO3 (LN) crystal. I also developed a method for the non reconfigurable generation of high-intensity multiple-cycle THz …
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Optimization of a Terahertz Radiator
At present, the utilization of the terahertz band for communications remains a hypothetical scenario. This thesis presents a design for a communications setup for terahertz frequencies of kilometer range distances using a reflector antenna design. The primary focus is the terahertz radiating …
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Terahertz optical frequency comb generation
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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Terahertz metamaterials for sensing and detection
… of metamaterials targeted for operation at terahertz frequencies was investigated including split-ring resonators, perfect absorbers, and flexible absorbers. The devices were designed through simulation by finite element method commercial software and fabricated by photolithographic lift-off …
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Semiconductor nanowires: towards enhanced terahertz sources
… achieving efficient electromagnetic radiation in terahertz (THz) frequency region by utilizing semiconductor nanowires due to advantages attributed to their one-dimensional structure, and also studying materials properties by adopting ultrafast THz time-domain spectroscopy (THz-TDS). In order to …
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Near-field imaging with terahertz pulses
… with a novel collection mode near-field terahertz (THz) probe. Exceptional sensitivity of the probe allows imaging with spatial resolution of few microns using THz pulses with spectral content of 120 to 1500 microns. In the present study, the principle of the probe operation as well as …
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Electrically tunable terahertz quantum cascade lasers
… systems (MEMS) assisted electrically tunable terahertz quantum cascade lasers (THz QCLs) are designed and demonstrated. Two MEMS tuner devices are proposed to achieve electrically tunable THz QCLs. One is the electrostatic comb drive actuated tuner design and the other one is a two-stage …
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Development of terahertz quantum-cascade lasers
The terahertz or the far-infrared frequency range of the electromagnetic spectrum ( ... ) has historically been technologically underdeveloped despite having many potential applications, primarily due to lack of suitable sources of coherent radiation. Following on the remarkable development of …
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Terahertz spectroscopy of quantum spin liquids
… ZnCu₃(OH)₆Cl₂, are studied by means of Terahertz Time-Domain Spectroscopy. Herbertsmithite is proposed to exhibit Quantum Spin Liquid behavior, in which electron spins have strong antiferromagnetic interactions, but quantum fluctuations inhibit magnetic order even at 0 K, instead giving …
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