Sökning: "bolometric effect"

Hittade 3 avhandlingar innehållade orden bolometric effect.

  1. 1. Spatiotemporal carrier dynamics in graphene

    Författare :Roland Jago; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spatiotemporal dynamics; density matrix formalism; graphene; relaxation dynamics; carrier multiplication; Bloch equations; photoconduction effect; bolometric effect;

    Sammanfattning : Graphene as an atomically thin material exhibits remarkable optical and electronic properties that suggest its technological application in novel optoelectronic devices, such as graphene-based photodetectors and lasers. To understand the properties of such devices on a microscopic level, we study the interplay of optical excitation, carrier-carrier, carrier-phonon, and carrierphoton scattering as well as diffusion processes. LÄS MER

  3. 2. NbN Hot Electron Bolometric Mixers for a Quasi--Optical THz Receiver

    Författare :Matthias Kroug; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bolometric mixer; superconducting NbN; heterodyne detection; hot electron effect; quasi-optical;

    Sammanfattning : 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. LÄS MER

  4. 3. Cold-Electron Bolometers fabricated with Direct Write Technology for Microwave Receiver systems

    Författare :Ernst Otto; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis concerns the development of microwave detector technology for cosmology instruments and THz imaging, including fabrication of SIN tunnel junctions for thermometry and bolometric detectors, and also phase switch circuits as a part of integrated microwave receiver systems. Cold-Electron Bolometers (CEB) based on Superconductor-Insulator-Normal metal (SIN) tunnel junctions have been developed for employment in sub-millimeter astronomical receivers. LÄS MER