Sökning: "bragg"

Visar resultat 1 - 5 av 68 avhandlingar innehållade ordet bragg.

  1. 1. Fibre Bragg Gratings : Characterization, Realization and Simulation

    Författare :Ingemar Petermann; Ari Friberg; Sten Helmfrid; Morten Ibsen; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Bragg gratings; optical fibres; optical fibre components; Physics; Fysik;

    Sammanfattning : The main topic of this thesis is realization and characterization of fibre Bragg gratings. A novel versatile grating fabrication technique is developed and a number of gratings are realized, showing the potential of the system. LÄS MER

  2. 2. Fibre Bragg Grating Components for Filtering, Switching and Lasing

    Författare :Zhangwei Yu; Lars Thylén; Pierre-Yves Fonjallaz; Lin Zhang; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; fibre Bragg grating; photosensitivity; apodization; chirp; phase-shift; microwave optical filtering; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : Fibre Bragg gratings (FBGs) are key components for a vast number of applications in optical communication systems, microwave photonics systems, and optical sensors, etc. The main topic of this thesis is fibre Bragg grating fabrication and applications in direct microwave optical filtering, high speed switching and switchable dual-wavelength fibre lasers. LÄS MER

  3. 3. Tandem optical parametric oscillators using volume Bragg grating spectral control

    Författare :Markus Henriksson; Fredrik Laurell; Hiromasa Ito; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; optical parametric oscillators; mid-infrared; volume Bragg gratings; PPKTP; ZGP; nonlinear optics; narrowband OPO; Physics; Fysik;

    Sammanfattning : This thesis describes research on near degenerate quasi phase-matched opticalparametric oscillators (OPO) where volume Bragg gratings (VBG) are used toproduce narrow oscillation bandwidth. These OPOs are then used to pump a secondOPO to generate mid-infrared radiation. The atmospheric transmission windows in the 3. LÄS MER

  4. 4. Thermal properties of volume Bragg gratings and its implications on lasers

    Författare :Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Mohamed Bourennane; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Thermal effects; Volume Bragg Gratings; VBG; Lasers;

    Sammanfattning : This thesis contains the results of research on the spectral control of lasers, specifically, the thermal limitations of volume Bragg gratings (VBGs), employed as laser-cavity end mirrors. The investigations consisted of both experiments and numerical simulations. LÄS MER

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

    Författare :Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Takunori Taira; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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