Sökning: "THz radiation"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden THz radiation.

1. 1. Modeling Quantum Cascade Lasers : The Challenge of Infra-Red Devices

   Författare :Martin Franckie; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Cascade Lasers; Non-equilibrium Green s functions; Modeling; semiconductor heterostructures; Quantum Cascade Lasers; Non-equilibrium Green s functions; THz radiation; infrared radiation; semiconductor heterostructures; Modeling Simulation Technology; Fysicumarkivet A:2016:Franckié;

   Sammanfattning : We live in a time of rapid scientific and technological advancement. People liv- ing 100 years ago could never dream of inventions like those having completely changed our way of life, and our perception of the world; computers, mobile phones, the Internet, space travel, unraveling the mysteries of the early universe and distant galaxies, and our insight into the microscopic world of quantum phe- nomena. LÄS MER

3. 2. Integration of Planar Antennas with MMIC Active Frontends for THz Imaging Applications

   Författare :Yogesh Karandikar; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sub-Harmonic Resistive Mixer; Planar Antennas; Gaussian Coupling; MMIC; Gilbert Cell Mixer; THz;

   Sammanfattning : In recent years, there has been constant growth in using THz frequencies or mm, sub- mm wavelengths for various applications such as: Astronomy, Atmospheric studies, security, bio-medical imaging. All these applications are now seen more feasible due to rapid enhancements of semi-conductor processing technologies. LÄS MER

4. 3. Superradiant THz wave emission from arrays of Josephson junctions

   Författare :Ievgenii Borodianskyi; Vladimir Krasnov; Yury Shukrinov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junction; Superconductor; ThZ emission; high-Tc; Physics; fysik;

   Sammanfattning : High-power, continuous-wave, compact and tunable THz sources are needed for a large variety of applications. Development of power-efficient sources of electromagnetic radiation in the 0.1-10 THz range is a difficult technological problem, known as the “THz gap. LÄS MER

5. 4. Ultrafast spin dynamics and relaxation in metallic ferromagnets

   Författare :Vivek Unikandanunni; Stefano Bonetti; Olof Karis; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetization dynamics; Three temperature model; Cobalt; Anisotropy; Electron-phonon coupling; THz; Platinum; Silver; fysik; Physics;

   Sammanfattning : We performed ultrafast demagnetization measurements on epitaxial hcp-cobalt thin film with the easy axis in the plane of the film by pumping the sample with 400 nm radiation and probing the magneto-optic effects in the longitudinal magneto optic Kerr effect geometry using 800 nm radiation. The in-plane magnetic anisotropy of the sample enabled us to measure the demagnetization dynamics along two different crystalline directions, namely along the easy axis and at 45 degrees between the easy and hard axes. LÄS MER

7. 5. Optical Analysis and Characterisation of the Climate Research Instrument STEAMR

   Författare :Arvid Hammar; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; limb viewing; Monte Carlo; Stratosphere-Troposphere Exchange And climate Monitor Radiometer STEAMR ; quasi optics; THz; antennas; multi-beam; tolerance analysis; submillimeter-wave instruments; radiometers;

   Sammanfattning : A growing interest for making high resolution observations in the upper troposphere and lower stratosphere has motivated the development of the multi-beam satellite-borne instrument Stratosphere-Troposphere Exchange And climate Monitor Radiometer (STEAMR). The measurements made by STEAMR will be used to monitor trace-gases and link the occurence of these to the Earth's climate by accurate modeling of the atmosphere. LÄS MER