Search for dissertations about: "optical mixers"
Showing result 1 - 5 of 9 swedish dissertations containing the words optical mixers.
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1. NbN Hot Electron Bolometric Mixers for a Quasi--Optical THz Receiver
Abstract : Experimental work on the development of a quasi-optical heterodyne receiver for the THz frequency range is reported. The mixing device is a superconducting hot electron bolometer (HEB) made from ultrathin, d = 3 - 5 nm, niobium nitride (NbN) films. READ MORE
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2. Antenna Integrated Superconducting Mixers
Abstract : This thesis investigates the prospects of some different superconducting mixers integrated with planar antennas for the millimeter and submillimeter regime. Two kinds of Superconductor/Insulator/Superconductor (SIS) tunnel junctions for use in mixers have been fabricated; Nb/PbBi edge junctions and Nb trilayer junctions. READ MORE
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3. Design and characterisation of terahertz Schottky diode harmonic mixers
Abstract : Efficient, compact, and reliable terahertz frequency converters preferably operating at ambient temperature are crucial for stabilising far-infrared optical sources. This thesis focuses on the design and characterisation of terahertz Schottky diode harmonic mixers for frequency stabilisation of quantum-cascade lasers. READ MORE
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4. Photonic terahertz-wave generation, radiation and quasioptical integration
Abstract : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. READ MORE
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5. Characterisation and Modelling of Graphene FETs for Terahertz Mixers and Detectors
Abstract : Graphene is a two-dimensional sheet of carbon atoms with numerous envisaged applications owing to its exciting properties. In particular, ultrahigh-speed graphene field effect transistors (GFETs) are possible due to the unprecedented carrier velocities in ideal graphene. READ MORE