Sökning: "Picosecond laser"

Visar resultat 16 - 20 av 37 avhandlingar innehållade orden Picosecond laser.

  1. 16. Properties of Volume Bragg Gratings and Nonlinear Crystals for Laser Engineering

    Författare :Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Takunori Taira; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volume Bragg grating; VBG; thermal effects; nonlinear optics; KTiOPO4; quasi-phase matching; photochromic damage; grey-tracking; color centers; blue-light induced infrared absorption; BLIIRA; Physics; Fysik;

    Sammanfattning : This thesis focuses on two topics: thermal limitations of volume Bragg gratings (VBGs) employed as laser-cavity mirrors and formation of color centers in KTiOPO4 and its isomorphs.To explore the mechanisms of the thermal limitations of VBGs in high power lasers, I designed and constructed a diode-pumped, solid‑state laser with a VBG as cavity mirror that had a significantly higher absorption than what is typical. LÄS MER

  3. 17. Picosecond Infrared Detection and Optical Mixing in YBa2Cu3O7-δ Thin Films

    Författare :Mikael Lindgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Studies of infrared photoresponse in high Tc superconducting YBa2Cu3O7-.delta. (YBCO) thin films are presented in this dissertation. LÄS MER

  4. 18. DEVELOPMENT OF A HIGH ENERGY TI:SAPPHIRE LASER FOR THE EXCITATION OF EXTREME ULTRAVIOLET LASERS

    Författare :Dale Martz; Jorge Rocca; Colorado State University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ;

    Sammanfattning : This dissertation describes the design, construction and characterization of a high energy chirped-pulse amplification Titanium-Sapphire laser system for the excitation of Extreme Ultraviolet (EUV) lasers. Compact EUV lasers have made possible nano-scale imaging, dense plasma diagnostics and photo-chemistry and photo-physics studies. LÄS MER

  5. 19. Short-Pulse Photofragmentation and Fluorescence-based Diagnostics - Development and Applications

    Författare :Malin Jonsson; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydroxyl radical OH ; Short-pulse excitation; Photofragmentation; Combustion diagnostics; Laser-induced fluorescence; Hydrogen peroxides; Collisional quenching; Fysicumarkivet A:2015:Jonsson;

    Sammanfattning : The work presented in the thesis covers the use of laser-induced fluorescence (LIF) and photofragmentation laser-induced fluorescence (PFLIF) with short laser pulses to determine species concentrations in different combustion environments. To attain quantitative species concentrations using LIF investigations of the influence of collisional quenching on the fluorescence signal strength is of vital importance, which can be done by measuring the fluorescence lifetime. LÄS MER

  7. 20. Development and Application of Pure Rotational CARS for Reactive Flows

    Författare :Alexis Bohlin; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Raman linewidths; gas-phase thermometry; combustion diagnostics; laser spectroscopy techniques; coherent anti-Stokes Raman scattering; molecular spectroscopy; Herman-Wallis factor; Fysicumarkivet A:2012:Bohlin;

    Sammanfattning : The thesis deals with the further development of pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) for improving the capabilities of gas phase thermometry. The main effort has been to make the technique more robust when employed under a wide range of temperatures and operational conditions. LÄS MER