Sökning: "Free Electron Lasers"

Visar resultat 1 - 5 av 46 avhandlingar innehållade orden Free Electron Lasers.

  1. 1. Efficiency Enhancement Techniques for Free-Electron Lasers

    Författare :Alan Mak; Lunds universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; free-electron laser; accelerator physics; efficiency enhancement; undulator tapering; phase jump method; synchrotron radiation; Fysicumarkivet:2017:Mak;

    Sammanfattning : The central question addressed in this thesis is how to make the free-electron laser (FEL) more efficient. In recent years, coherent diffraction imaging provides an important motivation for efficiency enhancement. This is because a more efficient FEL process enables converting a larger fraction of the electron beam's power into optical power. LÄS MER

  3. 2. Probing and improving coherence in Free-electron lasers

    Författare :Mihai Pop; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Accelerators; Free electron laser; Synchrotron radiation; Coherence; Young double-slit; spectrum analysis; Simulations;

    Sammanfattning : Free electron lasers or FELs, have transformed the way science has been done in the last decades by providing coherent, highly brilliant radiation at wavelengths not achievable with conventional lasers. Their most important characteristic, along side brightness, is their coherence, which allows users to perform experiments that rely on precise phase characteristics of the probing radiation. LÄS MER

  4. 3. Zone Plates for Hard X-Ray Free-Electron Lasers

    Författare :Daniel Nilsson; Ulrich Vogt; Thomas Tschentscher; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray optics; Zone plates; XFEL; x-rays; free-electron laser; heat transfer;

    Sammanfattning : Hard x-ray free-electron lasers are novel sources of coherent x-rays with unprecedented brightness and very short pulses. The radiation from these sources enables a wide range of new experiments that were not possible with previous x-ray sources. Many of these experiments require the possibility to focus the intense x-ray beam onto small samples. LÄS MER

  5. 4. Semiconductor Lasers with Gratings Defined by Electron Beam Lithography

    Författare :Torgil Kjellberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lasers; field-stitching errors; single-mode stability; fiber-optic communication;

    Sammanfattning : This thesis deals with the fabrication and characterization of semiconductor lasers with gratings defined by electron-beam lithography (EBL). Both distributed-feedback (DFB) lasers for fiber-optic communication and grating-surface-emitting (GSE) lasers suitable for a number of novel applications, from free-space communication to optical processing, are treated. LÄS MER

  7. 5. Nanofabrication of Zone Plates for Hard X-Ray Free-Electron Lasers

    Författare :Fredrik Uhlén; Ulrich Vogt; Thomas Wilhein; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray optics; Zone plates; Nanofabrication; X-ray free-electron lasers; Fysik; Physics;

    Sammanfattning : This Thesis describes the development of hard X-ray zone plates intended for focusing radiation at X-ray free-electron lasers (XFELs). XFELs provide unprecedented brightness and zone plates which are put in the intense X-ray beam are at risk of being damaged. LÄS MER