Sökning: "quasi phase-matching"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden quasi phase-matching.

1. 1. Concepts for compact solid-state lasers in the visible and UV

   Författare :Sandra Johansson; Fredrik Laurell; Patrick Georges; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; frequency conversion; visible lasers; ultraviolet lasers; KTiOPO4; BiBO; BBO; quasi phase-matching; birefringent phase-matching; solid-state lasers; Physics; Fysik;

   Sammanfattning : In many fields, scientific or industrial, optical devices that can be tailored in terms of spectral qualities and output power depending on the application in question are attractive. Nonlinear optics in combination with powerful laser sources provide a tool to achieve essentially any wavelength in the electromagnetic spectrum, and the advancement of material technology during the last decade has opened up new possibilities in terms of realising such devices. LÄS MER

3. 2. Components based on optical fibers with internal electrodes

   Författare :Niklas Myrén; KTH; []
   Nyckelord :Poling; twinhole fiber; fiber electrodes; silver film electrodes; silver diffusion; quasi-phase matching; optical switching; frequency conversion; optical modulation;

   Sammanfattning : The topic of this thesis is development ofdevices fortelecom applications based on poled optical fibers. The focusis on two different specific functions, wavelength conversionand optical switching.Optical switching is demonstrated in a poled optical fiberat telecom wavelengths (~1.55 mm). LÄS MER

4. 3. Nonlinear response in engineered optical materials

   Författare :Gustav Strömqvist; Valdas Pasiskevicius; Peter Smith; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; nonlinear index of refraction; double tungstates; periodic poling; KTiOPO4; quasi-phase matching; parametric down-conversion; mirrorless optical parametric oscillators;

   Sammanfattning : Material and structure engineering are increasingly employed in active optical media,in this context defined as media capable of providing laser or/and optical parametric gain. For laser materials, the main aim of the engineering is to tailor the absorption and emission cross sections in order to optimise the laser performance. LÄS MER

5. 4. Domain engineering in KTiOPO4

   Författare :Carlota Canalias; Fredrik Laurell; Benoît Boulanger; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quasi-phase matching; KTiOPO4; ferroelectric domains; atomic force microscopy; periodic electric field poling; polarization switching; second harmonic generation; Optical physics; Optisk fysik;

   Sammanfattning : Ferroelectric crystals are commonly used in nonlinear optics for frequency conversion of laser radiation. The quasi-phase matching (QPM) approach uses a periodically modulated nonlinearity that can be achieved by periodically inverting domains in ferroelectric crystals and allows versatile and efficient frequency conversion in the whole transparency region of the material. LÄS MER

7. 5. 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