Sökning: "optical collapse"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden optical collapse.

  1. 1. Nonlinear Propagation of Optical Pulses and Beams

    Författare :Magnus Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-phase modulation; optical wave breaking; paraxial-ray approximation; stimulated Raman scattering; nonlinear Schrödinger equation; optical collapse; modulational instability; higher-order dispersion; optical fibers; saturable nonlinearity; Kerr-nonlinearity; self-trapping; group-velocity dispersion; optical solitons; self-focusing;

    Sammanfattning : The propagation of optical beams and pulses under the influence of nonlinear effects is characterized by a rich variety of phenomena and many potentially important applications. We analyse two main topics in this context: nonlinear beam propagation, and nonlinear pulse propagation in optical fibers. LÄS MER

  3. 2. Nonlinear Theory of Partially Coherent Optical Waves

    Författare :Tobias Hansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; partial coherence; beam collapse; saturable logarithmic media; soliton interaction; dressing method; parabolic beams; Wigner transform; invariants; modulational instability;

    Sammanfattning : Nonlinear effects arise in optics as a consequence of the medium properties being modified by the presence of light. Of particular interest are situations where the effect of the nonlinearity can be described by an intensity dependent refractive index and the subsequent interplay with dispersion and diffraction. LÄS MER

  4. 3. Distributions Of Fiber Characteristics As A Tool To Evaluate Mechanical Pulps

    Författare :Sofia Reyier Österling; Per Engstrand; Hans Höglund; Olof Ferritsius; Rita Ferritsius; Hans Ersson; Per Gradin; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fiber; fibre; fiber characteristics; fiber dimension; fiber properties; mechanical pulp; FiberLab; raw data; distribution; fiber wall thickness; BIN; bonding ability influence; bonding indicator; bonding ability; fiber width; fibrillation; collapse resistance; laboratory sheet; fiber analyzer; optical analyzer; TMP; CTMP; SGW; sheet model; prediction; fiber characterization; hydrocyclone; fractionation; kernel density estimation; KDE; diffusion mixing; acoustic emission; F0.90; Norway spruce; Picea abies;

    Sammanfattning : Mechanical pulps are used in paper products such as magazine or news grade printing papers or paperboard. Mechanical pulping gives a high yield; nearly everything in the tree except the bark is used in the paper. This means that mechanical pulping consumes much less wood than chemical pulping, especially to produce a unit area of printing surface. LÄS MER

  5. 4. Observations of young core collapse supernova remnants

    Författare :Anestis Tziamtzis; Lundqvist Peter; Sergey Zharikov; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supernova remnants; Crab; SN 1987A; Astronomy; Astronomi; Astronomy; astronomi;

    Sammanfattning : Studies of young remnants offer an opportunity to test theoretical models of stellar evolution, explosion models and nucleosynthesis, as well as our understanding of the compact objects in the centre of the exploded stars.The first part of the thesis involves observations of the Crab nebula. LÄS MER

  7. 5. Dynamics of optical and X-ray responses of molecules

    Författare :Alexander Baev; KTH; []
    Nyckelord :two-photon absorption; collisional dephasing; resonant photoemission;

    Sammanfattning : The aim of this licentiatethesis is to investigate by means of theoretical simulationsthe dynamics of light scattering by molecules, with specialemphasis on molecules in gas phase and in solutions.The first part of the thesisconcerns the two-photon absorption (TPA) process in the opticalwavelength region. LÄS MER