Sökning: "THz radiation"

Visar resultat 21 - 22 av 22 avhandlingar innehållade orden THz radiation.

1. 21. Optical Parametric Devices in Periodically Poled LiTaO3

   Författare :Martin Levenius; Katia Gallo; Valdas Pasiskevicius; Giuseppe Leo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; parametric processes; frequency downconver-sion; quasi-phase matching; LiTaO3; broadband downconversion; quadratic cascading; nonlinear photonic crystals; twin-beam generation;

   Sammanfattning : Optical parametric frequency conversion based on quasi phase matching (QPM) in nonlinear optical crystals is a powerful technique for generating coherent radiation in wavelength ranges spanning from the mid-infrared (mid-IR) to the blue, displaying low thermal load and high efficiency.This thesis shows how QPM in one- (1D) or two-dimensional (2D) lattices can be employed to engineer novel devices for parametric downconversion in the IR, af-fording freedom in designing both spectral and angular properties of the parametric output. LÄS MER

3. 22. Nonlinear Properties of III-V Semiconductor Nanowaveguides

   Författare :Eleonora De Luca; Marcin Swillo; Fabrice Raineri; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optik och fotonik; Optics and Photonics;

   Sammanfattning : Nonlinear optics (NLO) plays a major role in the modern world: nonlinear optical phenomena have been observed in a wavelength range going from the deep infrared to the extreme ultraviolet, to THz radiation. The optical nonlinearities can be found in crystals, amorphous materials, polymers, liquid crystals, liquids, organic materials, and even gases and plasmas. LÄS MER