Sökning: "gratings"

Visar resultat 1 - 5 av 80 avhandlingar innehållade ordet gratings.

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

    Författare :Ingemar Petermann; Ari Friberg; Sten Helmfrid; Morten Ibsen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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

  3. 2. Grating-Coupled Surface-Emitting Lasers -- Circular and Unstable-Resonator Geometries

    Författare :Sigurgeir Kristjánsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laser beam focusing; grating coupled surface emitters; simulation; unstable resonator lasers; surface-emitting lasers; integrated optics; gratings; circular gratings; BPM simulations; laser resonators; semiconductor lasers; optical planar waveguide couplers; electron beam lithography;

    Sammanfattning : This thesis deals with research in the field of grating-coupled surface-emitting lasers. The emphasis has been to study the modal behavior of lasers with two different resonator geometries: circular resonators and tapered unstable-resonators. LÄS MER

  4. 3. Photosensitivity, chemical composition gratings and optical fiber based components

    Författare :Michael Fokine; KTH; []
    Nyckelord :optical fibers; fiber bragg gratings; photosensitivity; thermal stability; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : The different topics of this thesis include high-temperaturestable fiber Bragg gratings, photosensitivity and fiber basedcomponents. Fiber Bragg gratings (FBG) are wavelength dispersiverefractive index structures manufactured through UV exposure ofoptical fibers. LÄS MER

  5. 4. On diode-pumped solid-state lasers

    Författare :Jonas Hellström; Fredrik Laurell; Valdas Pasiskevicius; Klaus Petermann; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; near-infrared lasers; end-pumped lasers; Q-switching; erbium; ytterbium; GdCOB; KGW; KYW; Co:MALO; laser materials; thermal lensing; end-pumping; spectroscopy; conical refraction; volume Bragg gratings; holographic gratings; laser tuning; Physics; Fysik;

    Sammanfattning : The research that is presented in this thesis can be divided into two major parts. The first part concerns longitudinally pumped, bulk Er-Yb lasers. In these lasers, the main limitation is the thermal shortcomings of the phosphate glass host material. LÄS MER

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

    Författare :Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Mohamed Bourennane; KTH; []
    Nyckelord :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