Sökning: "Two-photon absorption"

Visar resultat 6 - 10 av 52 avhandlingar innehållade orden Two-photon absorption.

  1. 6. Light Control using Organometallic Chromophores

    Författare :Johan Henriksson; Patrick Norman; Olav Vahtras; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; organometallic chromophores; two-photon absorption; excited state absorption; excited state dipole moment; four-component formalism; clamping levels; spin-transition; Computational physics; Beräkningsfysik;

    Sammanfattning : The interaction between light and organometallic chromophores has been investigated theoretically in a strive for fast optical filters. The main emphasis is on two-photon absorption and excited state absorption as illustrated in the Jablonski diagram. We stress the need for relativistic calculations and have developed methods to address this issue. LÄS MER

  2. 7. Theoretical Characterization of Optical Processes in Modecular Complexes

    Författare :Kai Liu; Yi Luo; Benoît CHAMPAGNE; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; one-photon absorption; two-photon absorption; surface-enhanced Raman scattering; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : The main theme of this thesis is to study effects of different environments on geometric and electronic structures, as well as optical responses, of molecules using time-(in)dependent density functional theory. Theoretical calculations have been carried out for properties that can be measured by conventional and advanced experimental techniques, including one-photon absorption (OPA), two-photon absorption (TPA), surface-enhanced Raman scattering (SERS) and second order nonlinear optical (NLO) response. LÄS MER

  3. 8. Development and characterization of damped cubic response functions with application to two-photon absorption

    Författare :Tobias Fahleson; Patrick Norman; Joanna Kauczor; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Molecular response to electromagnetic fields - static or optical - within a framework of perturbation theory diverges close to resonance with molecular transitionen energies, and need work-around solutions for real-valued response functions. This licentiate thesis deals with nonlinear response, with focus being on cubic polarizaibilities, and outlines the underlying mathematics for exact-state and approximatestate, complex-valued response functions applicable to quantum chemical computation. LÄS MER

  4. 9. Photophysics of Perovskite Nano- and Microcrystals

    Författare :Junsheng Chen; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultrafast spectroscopy; Two-photon absorption; Perovskite; Nanocrystals; Photostability; Lead free perovskite;

    Sammanfattning : The demand and consumption of energy is increasing dramatically all around the world. Broad adoption of fossil fuels has triggered an enormous threat to the environment. To ensure sustainability of our species and habitat, new solutions to fulfill the energy demand have to be found. LÄS MER

  5. 10. Molecular Quadratic Response Properties with Inclusion of Relativity

    Författare :Johan Henriksson; Patrick Norman; Juha Vaara; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; relativistic quantum chemistry; molecular physics; clamping levels; four-component Hartree-Fock theory; Kohn-Sham density functional theory; response theory; nonlinear optics; second-harmonic generation; two-photon absorption; excited state properties; optical power limiting; Computational physics; Beräkningsfysik;

    Sammanfattning : This thesis concerns quadratic response properties and their application to properties in Jablonski diagrams such as resonant two-photon absorption and excited state absorption. Our main interest lies in optical power limiting applications, and in this context, molecules containing heavy metal atoms prove superior. LÄS MER