Search for dissertations about: "optical diffraction theory"

Showing result 1 - 5 of 21 swedish dissertations containing the words optical diffraction theory.

2. 1. Electromagnetic simulation and design of etched diffraction grating demultiplexers

   Author : Jun Song; Sailing He; Dries Van Thourhout; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; etched diffraction grating; wavelength division multiplexing; passive devices; diffraction grating; planar waveguide devices; DWDM; optical communication.; Photonics; Fotonik;

   Abstract : Among various planar lightwave circuits for multiplexing/demultiplexing in an optical communication system, etched diffraction gratings (EDGs) have shown great potential due to their compactness and high spectral finesse. Conventional numerical methods for grating simulation cannot be used to simulate an EDG demultiplexer of large size (in terms of the wavelength). READ MORE

4. 2. Optical Investigations of Chiral Liquid Crystals

   Author : Anders Dahlgren; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; antiferroelectric; de Vries theory; ferroelectric; optical activity; chiral; dielectric tensor; unwinding; liquid crystal; helicoidal; selective reflection;

   Abstract : Optical investigations of course involve experimental work, but a theoretical basis is also needed. The first chapter can hopefully can give the non-expert an insight into the science of liquid crystals. Liquid crystals are optically birefringent, and a review of the phenomenon of birefringence follows in chapter 2. READ MORE

5. 3. Axicon imaging by scalar diffraction theory

   Author : Anna Burvall; KTH; []
   Keywords : axicons; diffractive optics; coherence; asymptotic methods; communication modes; information content; inverse problems;

   Abstract : Axicons are optical elements that produce Bessel beams,i.e., long and narrow focal lines along the optical axis. Thenarrow focus makes them useful ine. READ MORE

6. 4. The interaction of hydrogen with metallic glass

   Author : Johan Bylin; Gunnar K. Pálsson; Ralph H. Scheicher; Gabriella Andersson; Astrid Pundt; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; metallic glass; hydrogen; thin film; density functional theory; stochastic quenching; molecular dynamics; x-ray diffraction; pair distribution function; neutron reflectometry; volume expansion; elastic hydrogen-hydrogen interaction; dipole force tensor; electronic structure; optical conductivity; resistivity; optical transmission; x-ray photoelectron spectroscopy; thermodynamic driving force; Gibbs free energy; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Abstract : Combining theoretical ab initio calculations with high-purity thin film sample synthesis and in situ measurements is a compelling way to bridge the gap in our understanding concerning hydrogen in metallic glasses, which is the primary work of this dissertation thesis. The main emphasis has been on how hydrogen affects the structure of metallic glasses, and how those changes influence not only the electronic properties of the amorphous metals but also their thermal stability. READ MORE

7. 5. Optical Imaging for Nanowire Mechanics

   Author : Monica Lexholm; Fasta tillståndets fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; sensor applications; optical imaging; nanowire mechanics; Fysicumarkivet A:2010:Lexholm;

   Abstract : In this work, we present a stroboscopic detection technique for the study of oscillating nanoscale objects. This optical read-out gives a position accuracy better than 1 nm which is a fraction of both the diffraction limit and the pixel size. READ MORE