Global ETD Search
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Showing 1 to 10 of 10 for “"THz quantum cascade lasers"”.
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New frontiers in THz quantum cascade lasers
Terahertz (THz) frequencies (0.5-10 THz) are among the most underdeveloped electromagnetic spectra, even though their application potentials are great in imaging, sensing, and communications. This underdevelopment is primarily due to the lack of compact and powerful THz sources. The invention of …
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Electromagnetic modeling of terahertz quantum cascade laser waveguides and resonators
… waveguides and resonators used in terahertz (THz) quantum cascade lasers (QCLs) is presented. Simulations and analysis of two types were performed: two-dimensional waveguides, and two- and three-dimensional resonators. Both metal-metal and semi-insulating (SI) surface-plasmon geometries were …
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Theory of terahertz intervalence band polaritons and antipolaritons.
… investigation of the interaction of terahertz (THz) radiation with intersubband excitations in microcavities leading to THz polaritons and antipolaritons. The approach is based on the dielectric function formalism. The dielectric constant is derived from an optical susceptibility evaluated with …
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Towards multiple quantum well optically pumped far infrared lasers
Optically pumped lasers based on GaAs/AlGaAs multiple quantum well (MQW) structures are a potential coherent source in the far infrared (FIR) wavelengths. The FIR (~ 30 to 300 µm) is a region within the electromagnetic spectrum that has seen relatively little development. No practical solid-state …
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Development of Active Terahertz Modulators for use with Quantum Cascade Lasers and Near-Field Imaging of their Individual Resonators
… techniques and characterised using terahertz (THz) time-domain spectroscopy (TDS). Devices designed to modulate the phase and frequency of the transmitted and reflected THz radiation were fabricated and characterised operating at ∼ 1.5 THz and 3 THz. Both the 3 THz and 1.5 THz devices were …
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Novel waveguides for terahertz quantum cascade lasers
… their first demonstration in 2002, terahertz (THz) quantum cascade lasers (QCLs) have proven to be one of the most reliable sources of this type of radiation. Advances have been made in increasing maximum operating temperature, shaping the beam and tuning the frequency and bandwidth. Waveguide …
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Novel Applications of Terahertz Quantum Cascade Lasers: Gas Spectroscopy, Active Control & Nearfield Imaging
Since the advent of Terahertz (THz) quantum cascade lasers (QCLs) in 2002, they have seen significant improvement in output power, operating temperature, and spectral coverage as well as having been widely applied to astronomical applications, imaging, and spectroscopy because of their high output …
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Graphene Integrated Metamaterial Devices for Terahertz Modulation
Terahertz (THz) research has experienced impressive progress in recent decades, with unique applications emerging in fields such as spectroscopy, communications, and imaging, all of which require fast and accurate control of the THz radiation properties. To unlock the full potential of THz …
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Laterally confined THz sources and graphene based THz optics
… in the electromagnetic spectrum, the Terahertz (THz) gap, provides an exciting opportunity for future wireless communications as this band has been under utilised. This doctoral work takes a two-pronged approach into closing the THz gap with low-dimensional materials. The first attempt addresses …