Sökning: "Grating"

Visar resultat 6 - 10 av 115 avhandlingar innehållade ordet Grating.

1. 6. Fibre Bragg Grating Components for Filtering, Switching and Lasing

   Författare :Zhangwei Yu; Lars Thylén; Pierre-Yves Fonjallaz; Lin Zhang; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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. 7. Infrared Laser-Induced Grating Techniques for Diagnostics in Reactive Flows

   Författare :Dina Hot; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser diagnostics; infrared; laser-induced grating spectroscopy; degenerate four-wave mixing; flames; temperature; concentration; Fysicumarkivet A:2020:Hot;

   Sammanfattning : AbstractThe work presented in this thesis is mainly focused on the development andapplication of infrared laser-induced grating techniques in order to measure the gasphase temperature and species concentrations in reactive flows. The two techniquesused for this purpose are laser-induced grating spectroscopy (LIGS) and degeneratefour-wave mixing (DFWM). LÄS MER

4. 8. 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

5. 9. Multifunctional Waveguide Grating Couplers for Integrated Optics

   Författare :Johan Backlund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This thesis describes a novel waveguide component in integrated optics called a multifunctional grating coupler. It couples light in or out of optical waveguides and provides additional optical functions such as beam splitting, arbitrary focusing, polarization sensing, and wavelength separation (wavelength division demultiplexing). LÄS MER

7. 10. Grating Based Lasers for Photonic Integration and Surface Emission

   Författare :Peter Modh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; integrated optics; surface-emitting lasers; laser resonators; optical planar waveguide couplers; unstable-resonator lasers; semiconductor lasers;

   Sammanfattning : This thesis deals with the fabrication and characterization of grating-based integration-compatible semiconductor lasers. Waveguide gratings provide feedback for the laser resonators, and are used to diffract the laser output out of the waveguide for surface-emission. LÄS MER