Search for dissertations about: "multi-photon excitation"

Showing result 1 - 5 of 10 swedish dissertations containing the words multi-photon excitation.

2. 1. Resonant multi-photon ionisation studies of high-energy states in small molecules

   Author : Marica Sjödin; Lars-Erik Berg; Arne Rosén; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

   Abstract : This thesis describes separate studies of high-energy Rydberg and ion-pair states in small molecules using resonant multi-photon ionisation spectroscopy. * OODR/REMPI study of ungerade Rydberg states in O2 The energy region between 75000 and 99900 cm-1 of O2 has been studied using optical-optical double resonance (OODR) with resonance enhanced multi-photon ionisation (REMPI). READ MORE

4. 2. Nonlinear optical techniques for ultrafast laser diagnostics : Development of femtosecond LIF, LIGS, CARS and backward lasing

   Author : Maria Ruchkina; Förbränningsfysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; laser diagnostics; femtosecond laser; nonlinear interactions; ultrafast spectroscopy; multi-photon excitation; laser-induced fluorescence; rotational coherent anti-Stokes Raman spectroscopy; laser-induced grating spectroscopy; lasing; backward lasing technique; Fysicumarkivet A:2021:Ruchkina;

   Abstract : The thesis work concerns development and application of four versatile nonlinear optical techniques, based on exploiting ultrashort laser pulses, for diagnostic purposes in gases and flames. The four techniques, all laser-based, are two-photon laser-induced fluorescence (TPLIF), hybrid femtosecond/nanosecond (fs/ns) rotational coherent anti-Stokes Raman scattering (fs/ns RCARS), fs-laser-induced grating spectroscopy (fs-LIGS), and backward lasing. READ MORE

5. 3. Multi-photon microscopy enhanced: Exploring annular beams and gold nano-particles for improved imaging

   Author : Johan Borglin; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Multiphoton microscopy; Beam shaping; Gold nanoparticles;

   Abstract : Laser scanning multiphoton microscopy (MPM) has emerged as a powerful tool for non-invasive three-dimensional imaging of biological tissue. The localized focal region enables confocality without the use of a physical pinhole while providing less photobleaching and photodamage compared to confocal laser scanning microscopy. READ MORE

6. 4. Quantum chemical calculations of non-linear optical absorption

   Author : Peter Cronstrand; KTH; []
   Keywords : quantum chemical; non-linear optical; multi-photon absorption;

   Abstract : This thesis represents a quantum chemical treatise ofvarious types of interactions between radiation and molecularsystems, with special emphasis on the nonlinear opticalprocesses of Multi-Photon Absorption and Excited StateAbsorption. Excitation energies, transition dipole moments,two-photon and three-photon tensor elements have beencalculated from different approaches; density functional theoryandab-initiotheory, employing different orders ofcorrelation treatment with the purpose to provide accuratevalues as well as evaluate the quality of the lower ordermethods. READ MORE

7. 5. Two-Photon Excited Fluorescence Depolarisation : Experimental and Theoretical Development

   Author : Linus Ryderfors; Emad Mukhtar; Lennart B.-Å. Johansson; Yehudi K. Levine; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Two-photon excitation; Fluorescence; Fluorescence depolarisation; Fluorescence anisotropy; Time-correlated single photon counting; Gold nanoparticles; Rotational diffusion; Excited state symmetry; Extended Förster theory; Orientation correlation functions; Donor-donor energy migration DDEM ; Chemical physics; Kemisk fysik;

   Abstract : We have studied fundamental aspects of time-resolved two-photon excited fluorescence depolarisation. The thesis presents experimental as well as theoretical progress. READ MORE