Sökning: "Gaussian beams"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Gaussian beams.

  1. 1. Propagation of some coherent and partially coherent laser beams

    Detta är en avhandling från Stockholm : KTH

    Författare :Yangjian Cai; KTH.; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : dark hollow beam; elliptical Gaussian beam; flat-topped beam; twisted anisotropic Gaussian Schell-model; partial coherent; propagation; paraxial optical system; TECHNOLOGY Electrical engineering; electronics and photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik;

    Sammanfattning : In this thesis, we investigate the propagation of some coherent and partially coherent laser beams, including a dark hollow beam (DHB), an elliptical Gaussian beam (EGB), a flat-topped beam and a twisted anisotropic Gaussian Schell-model (TAGSM) beam, through a paraxial optical system or a turbulent atmosphere. Several theoretical models are proposed to describe a DHB of circular or non-circular symmetry. LÄS MER

  2. 2. Numerical Methods for Wave Propagation Analysis and Applications in Quantum Dynamics

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Emil Kieri; Uppsala universitet.; Uppsala universitet.; [2016]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computational wave propagation; quantum dynamics; time-dependent Schrödinger equation; spectral methods; Gaussian beams; splitting methods; low-rank approximation; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : We study numerical methods for time-dependent partial differential equations describing wave propagation, primarily applied to problems in quantum dynamics governed by the time-dependent Schrödinger equation (TDSE). We consider both methods for spatial approximation and for time stepping. LÄS MER

  3. 3. Topics in Analysis and Computation of Linear Wave Propagation

    Detta är en avhandling från Stockholm : KTH

    Författare :Mohammad Motamed; KTH.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MATHEMATICS Applied mathematics Numerical analysis; MATEMATIK Tillämpad matematik Numerisk analys;

    Sammanfattning : This thesis concerns the analysis and numerical simulation of wave propagation problems described by systems of linear hyperbolic partial differential equations.A major challenge in wave propagation problems is numerical simulation of high frequency waves. LÄS MER

  4. 4. Terrain navigation for underwater vehicles

    Detta är en avhandling från Stockholm : KTH

    Författare :Ingemar Nygren; KTH.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling;

    Sammanfattning : In this thesis a terrain positioning method for underwater vehicles called the correlation method is presented. Using the method the vehicle can determine its absolute position with the help of a sonar and a map of the bottom topography. LÄS MER

  5. 5. DEVELOPMENT OF A HIGH ENERGY TI:SAPPHIRE LASER FOR THE EXCITATION OF EXTREME ULTRAVIOLET LASERS

    Detta är en avhandling från ProQuest/UMI

    Författare :Dale Martz; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SRA - E-Science SeRC ; SRA - E-vetenskap SeRC ;

    Sammanfattning : This dissertation describes the design, construction and characterization of a high energy chirped-pulse amplification Titanium-Sapphire laser system for the excitation of Extreme Ultraviolet (EUV) lasers. Compact EUV lasers have made possible nano-scale imaging, dense plasma diagnostics and photo-chemistry and photo-physics studies. LÄS MER