Sökning: "Quantum cascade"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden Quantum cascade.

  1. 1. Lineshape in Quantum Cascade Lasers - Temperature, Screening and Broadening

    Författare :Rikard Nelander; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Cascade Lasers; quantum wells; spectral lineshape; Non-Equilibrium Green s Functions; screening; temperature dependence;

    Sammanfattning : This dissertation deals with the optical properties of Quantum Cascade Lasers (QCLs). Studies are performed using transport calculations employing the theory of Non-Equilibrium Green's Functions, and screening is studied within the Random Phase Approximation. Focus is put on the temperature dependent effects in THz QCLs. LÄS MER

  3. 2. Dynamical Analysis of Terahertz Quantum Cascade Lasers

    Författare :Denizhan Ekin Önder; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; quantum cascade lasers; electric field domains; chaos; simulation; Fysicumarkivet A:2023:Önder;

    Sammanfattning : This thesis focuses on various aspects in terahertz quantum cascade lasers such as high temperature performances, electrical instabilities and chaos. In the first part of the thesis, an introduction to the topic and the non equilibrium Green's function package applied is given with particular emphasise on the inhomogeneous domain model and the chaos theory. LÄS MER

  4. 3. Optical Studies of Single Quantum Dots

    Författare :Jonas Persson; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nano-optics; quantum optics; photoluminescence; micro-photoluminescence; single photon generation; Semiconductory physics; Halvledarfysik; low-dimensional structures; quantum dots; Stranski-Krastanow; Fysicumarkivet A:2004:Persson;

    Sammanfattning : This thesis presents spectroscopic studies of single self-assembled InP quantum dots (QDs). The electronic properties of these QDs have been studied by photoluminescence (PL) and scanning tunnelling luminescence (STL). The QDs were grown in the Stranski-Krastanow mode and were embedded in GaInP. LÄS MER

  5. 4. 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

  7. 5. Quantitative Modeling of Gain in Quantum Cascade Lasers under Operational Intensities

    Författare :David Winge; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; non-linear response; quantum cascade lasers; modelling; Non-equilibrium Green s functions; Gain clamping; Fysicumarkivet A:2016:Winge; kvantkaskadlaser; terahertz; infrarött; Halvledarfysik; spektroskopi; simulering;

    Sammanfattning : This thesis adresses modeling of quantum cascade lasers using non-equilibrium Green’s functions. Focus lies on the quantitative modeling of the gain when the systems are exposed to strong laser fields, as under realistic opertional conditions. LÄS MER