Terahertz wave sensitive superconducting bolometric detector için kapak resmi
Terahertz wave sensitive superconducting bolometric detector
Başlık:
Terahertz wave sensitive superconducting bolometric detector
Yazar:
Semerci, Tuğçe, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xii, 102 leaves: color illustraltions.+ 1 computer laser optical disc.
Özet:
Terahertz (THz) waves has varied properties than other part of the electromagnetic spectrum which between microwave and infrared and has 0.3-10 THz frequency range and 3-0.03 mm wavelength. There are many areas to utilize from THz radiation that defense industry particularly security part such as detecting of unknown materials, poison or explosive matters. Additionally, THz waves can pass through leather, fabric and paper despite of metal and water and there is no enough energy to ionize the atoms in THz radiation. That’s why, THz radiation is not hazardous for human. Many detectors are developed to use these benefit of THz radiation. Bolometric detector is preferred between these detectors to detect the radiation above 1 THz frequency. Bi2Sr2CaCu2O8+δ (Bi2212) single crystal was used in literature for the first time to detect the THz waves with superconducting bolometers with our study. In this study, epoxy was used to transfer Bi2212 single crystal onto the sapphire substrate. Intended thickness was acquired by scotch tape via cleaved crystal mechanically. Edge of crystals were cut pyramid shape to provide each layer to contact with gold, crystal and silver epoxy. 150-200 nm crystals were shadowed by aluminum foil to deposit roughly 200 nm gold. Then clean room process was implemented to prepare our samples to electron beam lithography. Log-periodic antenna and four point contact structure was placed onto the crystals then UV light, developer and ion beam etching system were performed. Cryostat was designed and produced to measure electrical and bolometric measurements. Resistance-temperature in a-b axis gave the around 90 K as critical temperature. Bolometric measurement was done via superconducting transition region to decide the selected temperature to measure the change of resistance by sending signal from Stefan-Boltzmann Lamp in specific seconds. Change of resistance was observed from resistance-time measurement for bolometric measurement. Response time was calculated approaching 825 ms from the result of bolometric measurement. Our measurement set-up has limitation to read right data. Lock-in-amplifier may use to more accurate result.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology:Materials Science and Engineering.

İzmir Institute of Technology:Materials Science and Engineering--Thesis (Master).
Elektronik Erişim:
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