Essays about: "optical lattice"

Showing result 1 - 5 of 22 essays containing the words optical lattice.

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

    University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Author : Isa Clementsson; [2023]
    Keywords : Physics and Astronomy;

    Abstract : 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. READ MORE

  3. 2. Hydrogen Absorption in Metal Hydrides : Transmission of light in relation to hydrogen concentration and site occupancy of ultrathin vanadium films

    University essay from Uppsala universitet/Tillämpad kärnfysik

    Author : David Sörme; [2022]
    Keywords : metal hydrides; iron-vanadium superlattice; hydrogen; hydrogen site occupancy; hydrogen concentrationm; hydrogen storage;

    Abstract : In this study the effect of hydrogenation on the optical properties in the wavelength range 400-1023 nm of an ultrathin iron-vanadium superlattice is investigated. Specifically, mea- surements of transmission are performed under different states of hydrogenation, along with measurements of absolute hydrogen concentration and hydrogen site occupancy. READ MORE

  4. 3. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

    University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Author : Lassi Linnala; [2022]
    Keywords : femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

    Abstract : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. READ MORE

  5. 4. A study of optical and structural properties of spin-coated V2O3 thin films on sapphire substrates

    University essay from Linköpings universitet/Institutionen för fysik, kemi och biologi

    Author : Jennifer Silander; [2022]
    Keywords : Optical properties; transmittance; FTIR spectrometry; scanning electron microscopy; x-ray diffraction; metal-insulator transition; crystalline material; sol-gel; spin-coating; vanadium oxide; infrared light;

    Abstract : Many transition metal oxides exhibit a Metal-Insulator Transition (MIT). This is an interesting phenomenon where the material undergoes a structural phase transition, and the electronic charge is redistributed in the crystal lattice. READ MORE

  6. 5. Topological Photonic Lattices

    University essay from KTH/Tillämpad fysik

    Author : Zesheng Xu; [2022]
    Keywords : Topological photonics; Integrated photonics; Condensed matter physics physics; Optics; Topologisk fotonik; integrerad fotonik; fysik för kondenserad materia; Optik;

    Abstract : Topological Photonics is a rapidly growing field which explores the ideas of topological invariants adapted from condensed matter physics to optical systems. Thanks to integrated photonics platforms, the evolution of light in nanoscale photonic lattices can enable direct measurement of topological properties of the band-structure. READ MORE