Sökning: "ultrashort"

Visar resultat 1 - 5 av 28 uppsatser innehållade ordet ultrashort.

  1. 1. Quantum Optical Description of High-order Harmonic Generation

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Isabel Moreno; [2024]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : High-order Harmonic Generation (HHG) is a highly non-linear process in which an atom interacts with a strong laser field. The laser field lowers the atomic potential barrier allowing bound electrons to escape into the continuum through tunnel ionization, propagate, and, with some probability, recombine with the parent ion. LÄS MER

  3. 2. Towards a setup for narrowband terahertz generation through difference-frequency mixing of chirped ultrashort pulses

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Isa Clementsson; [2023]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : Terahertz radiation is a useful tool for inducing lower-energy excitations in matter, where it can be used to cause structural changes through direct interaction with the crystal lattice. Sub-picosecond optical pulses can be used to generate intense broadband terahertz pulses through optical rectification in nonlinear crystals, reaching peak electric fields of several MV/m and conversion efficiencies as high as a few percent. LÄS MER

  4. 3. Spectral broadening of 4 mJ femtosecond pulses using a bulk multi-pass cell

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Saga Westerberg; [2023]
    Nyckelord :Lasers; Ultrashort; Nonlinear Optics; femtosecond; Multi-Pass Cell; Spectral broadening; pulse post-compression; Self phase modulation; Physics and Astronomy;

    Sammanfattning : Nonlinear optical effects can be used for spectral broadening, which the basis of the field of post-compression of laser pulses. When the intensity of light becomes high enough the refractive index becomes intensity dependent, and as the intensity often varies both with position and time so does the refractive index. LÄS MER

  5. 4. Simulations of stray radiation in the European XFEL undulators with the Geant4 toolkit

    Kandidat-uppsats, Stockholms universitet/Fysikum

    Författare :Guillermo Lopez Basurco; [2022]
    Nyckelord :Geant4; Monte Carlo simulations; XFEL undulators; gamma radiation flux;

    Sammanfattning : The European XFEL is an X-ray free electron laser research facility that generates ultrashort, high intensity flashes. Three SASE undulator systems are made of undulator segments and intersection components. LÄS MER

  7. 5. Multi-spectral X-ray imaging with a laser-plasma accelerator

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Andrea Angella; [2022]
    Nyckelord :Multi-spectral imaging; single-photon counting; X-ray absorption spectroscopy; XAS; LWFA; laser-wakefield acceleration; K-edge; imaging; metal-detection algorithm; Physics and Astronomy;

    Sammanfattning : This master thesis focuses on the creation of an algorithm to perform multispectral imaging of a metallic target using X-rays. The generation of an ultrashort high-power low-divergent X-ray beam is performed by means of a Ti:Sapphire laser driven wake-field plasma accelerator. LÄS MER