Sökning: "thermal reshaping"

Hittade 4 avhandlingar innehållade orden thermal reshaping.

  1. 1. Optical manipulation and heating of gold nanoparticles near interfaces

    Författare :Daniel Andrén; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LSPR spectroscopy; particle-surface separation distance; thermal reshaping; TIRM; nanomotor; plasmonics; photothermal effects; Brownian dynamics; gold nanorod; optical tweezers;

    Sammanfattning : By focusing laser light to small volumes, its momentum can be used to trap and manipulate objects in the size range from cells down to single atoms. Devices using this effect are called optical tweezers, and have found use in measuring and applying minuscule forces and torques, contributed to deepening our knowledge of molecular motors, unraveling the mechanics of cells and DNA, and better understand statistical mechanics and hydrodynamic interactions at the nanoscale. LÄS MER

  3. 2. 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

  4. 3. 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

  5. 4. Plasma assisted technology for Si-based photonic integrated circuits

    Författare :Matteo Dainese; Lars Thylén; Alfred Driessen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; silica-on-silicon technology; PACVD; plasma deposition; photonic integrated circuits; planar lightwave circuits; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : The last two decades have witnessed a large increase in capacity in telecommunication systems, thanks to the development of high bandwidth, fiber optic based networks. Nevertheless the continuing growth of Internet data traffic, fuelled by the development of numerous services like on-line commerce, video on demand, large audio/video files downloads, demands for a significant increase in the ability of the network nodes to manage incoming and outcoming data streams effectively and fast. LÄS MER