Blar i NTNU Open på forfatter "Österberg, Ulf Lennart"

Viser treff 1-7 av 7

    • All-optical high-speed modulation of THz transmission through silicon core optical fibers 

      Sørgård, Trygve Reinertsen; Hawkins, Thomas; Ballato, John; Österberg, Ulf Lennart; Gibson, Ursula (Journal article; Peer reviewed, 2021)
      High speed optical modulation of THz radiation is of interest for information processing and communications applications. In this paper infrared femtosecond pulses are used to generate free carriers that reduce the THz ...

    • Broadband infrared and THz transmitting silicon core optical fiber 

      Sørgård, Trygve; Song, Seunghan; Vullum, Per Erik; Kores, Cristine; Mølster, Kjell Martin; Laurell, Fredrik; Hawkins, Thomas A.; Ballato, John; Österberg, Ulf Lennart; Gibson, Ursula (Peer reviewed; Journal article, 2020)
      Silicon waveguide structures are a viable alternative for the transmission of signals over a wide range of frequencies, and new fabrication methods are key to increased applications. In this work, THz transparency of ...

    • Multilevel Maxwell-Bloch simulations in inhomogeneously broadened media 

      Marskar, Robert; Österberg, Ulf Lennart (Journal article; Peer reviewed, 2011)
      A compact numerical method for simulating ultrafast pulse interaction with inhomogeneously broadened multi-level media is reported. We use a low-dispersion pseudospectral scheme with fourth order time stepping for Maxwell’s ...

    • Terahertz Time-Domain Spectroscopy of Thin Material Samples 

      Sørgård, Trygve Reinertsen (Master thesis, 2015)
      This thesis describes the techniques used in terahertz time-domain spectroscopy to determine the optical properties of layers that are thin compared to the length of the terahertz pulse. An iterative procedure is used to ...

    • Terahertz waveguiding in glass+clad silicon wafers 

      Sørgård, Trygve; Mølster, Kjell Martin; Laurell, Fredrik; Pasiskevicius, Valdas; Gibson, Ursula; Österberg, Ulf Lennart (Journal article; Peer reviewed, 2020)
      The waveguiding properties of high-resistivity float zone silicon slab waveguides are characterized over the spectral range from 0.5 to 7.5 THz. Waveguide modes and dispersion are observed for lengths of 1.2 cm and silicon ...

    • Thickness dependent uniaxial magnetic anisotropy due to step-edges in (1 1 1)-oriented La0.7Sr0.3MnO3 thin films 

      Bolstad, Torstein; Lysne, Erik Nikolai; Österberg, Ulf Lennart; Tybell, Per Thomas Martin (Journal article; Peer reviewed, 2019)
      The magnetic anisotropy of films of La0.7Sr0.3MnO3 grown on vicinal (1 1 1)-oriented SrTiO3 substrates are investigated. For temperatures above the tetragonal – cubic structural phase transition temperature of the substrate, ...

    • Time-domain spectroscopy of KTiOPO4 in the frequency range 0.6 - 7.0 THz 

      Mølster, Kjell Martin; Sørgård, Trygve; Laurell, Hugo; Canalias, Carlota; Pasiskevicius, Valdas; Laurell, Fredrik; Österberg, Ulf Lennart (Journal article; Peer reviewed, 2019)
      We report on THz time-domain spectroscopy measurements of flux grownKTiOPO4in the frequency range 0.6–7.0 THz (20 to 240 cm−1). Our results compare well with earlierRaman and far-infrared measurements. We theorize that the ...