Search for dissertations about: "Optical absorption"

Showing result 1 - 5 of 427 swedish dissertations containing the words Optical absorption.

  2. 1. Cavity enhanced optical sensing

    Author : Isak Silander; Ove Axner; Aleksandra Foltynowicz; Jong Chow; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Optical resonators; Fiber Laser; Parametric oscillators; Optical frequency comb; Infrared; Spectroscopy heterodyne; Spectroscopy molecular; Absorption; Dispersion; Lineshapes; Optical standards and testing; Refractivety measurements;

    Abstract : An optical cavity comprises a set of mirrors between which light can be reflected a number of times. The selectivity and stability of optical cavities make them extremely useful as frequency references or discri­mi­nators. READ MORE

  4. 2. Tailoring the Optical Response of III-V Nanowire Arrays

    Author : Mahtab Aghaeipour; Håkan Pettersson; Mats-Erik Pistol; Nicklas Anttu; Lars Samuelson; Constance J. Chang-Hasnain; NanoLund: Centre for Nanoscience; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; III-V nanowires; absorption; optical modes; photovoltaics; III-V nanowires; absorption; optical modes; photovoltaics; Fysicumarkivet A:2017:Aghaeipour;

    Abstract : Semiconductor nanowires show a great deal of promise for applications in a wide range of important fields, including photovoltaics, biomedicine, and information technology. Developing these exciting applications is strongly dependent on understanding the fundamental properties of nanowires, such as their optical resonances and absorption spectra. READ MORE

  5. 3. Mid-infrared photonic devices for on-chip optical gas sensing

    Author : Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mid-infrared; mid-IR; photonics; silicon photonics; gas sensing; optical sensing; optical gas sensing; spectroscopy; absorption; dispersion; carbon dioxide; CO2; CO2 sensing; trace gas; ethanol sensing; alcohol sensing; waveguide; photonic waveguide; ring resonator; nanowire; nanoheater; emitter; thermal source; bolometer; microbolometer; thermal detector; high frequency; 3 omega method; plasmonic; platinum; Kanthal; silicon-on-insulator; micro-electro-mechanical systems MEMS ; microfabrication; microsystems; microtechnology; nanotechnology; Optik och fotonik; Optics and Photonics; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. READ MORE

  6. 4. Laser-based absorption spectrometry : development of NICE-OHMS towards ultra-sensitive trace species detection

    Author : Florian Schmidt; Ove Axner; Livio Gianfrani; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; trace species detection; fiber laser; modulation; cavity-enhanced spectroscopy; optical saturation; laser frequency stabilization; free-spectral-range; Physics; Fysik;

    Abstract : Laser-based absorption spectroscopy (AS) is a powerful technique for qualitative and quantitative studies of atoms and molecules. An important field of use of AS is the detection of species in trace concentrations, which has applications not only in physics and chemistry but also in biology and medicine, encompassing environmental monitoring, regulation of industrial processes and breath analysis. READ MORE

  7. 5. Quantum chemical calculations of non-linear optical absorption

    Author : Peter Cronstrand; KTH; []
    Keywords : quantum chemical; non-linear optical; multi-photon absorption;

    Abstract : This thesis represents a quantum chemical treatise ofvarious types of interactions between radiation and molecularsystems, with special emphasis on the nonlinear opticalprocesses of Multi-Photon Absorption and Excited StateAbsorption. Excitation energies, transition dipole moments,two-photon and three-photon tensor elements have beencalculated from different approaches; density functional theoryandab-initiotheory, employing different orders ofcorrelation treatment with the purpose to provide accuratevalues as well as evaluate the quality of the lower ordermethods. READ MORE