Sökning: "Optical Methods"

Visar resultat 16 - 20 av 684 avhandlingar innehållade orden Optical Methods.

  1. 16. Aspects of Optical Broad Band Spectroscopy and Information Extraction - Applications in Medicine and Ecology

    Författare :Mikkel Brydegaard; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fluorescence Spectroscopy; Optical diagnostics; Electro-optics; Applied spectroscopy; Multispectral imaging; Optical spectroscopy; LIDAR; Remote sensing; Environmental monitoring; Chemometrics; Fysicumarkivet A:2012:Brydegaard Sörensen;

    Sammanfattning : The present thesis describes a number of aspects of modern electro-optical measurement technology also known as bio-photonics; this includes instrumentation, applications, sample interaction and data interpretation. The methods employed operate over several domains, and light measurements are discretized both in intensity, space, angle, time, polarization and energy. LÄS MER

  3. 17. Frequency Noise in Coherent Optical Systems: Impact and Mitigation Methods

    Författare :Aditya Kakkar; Richard Schatz; Sergei Popov; Gunnar Jacobsen; Xiaodan Pang; Oskars Ozolins; Magnus Karlsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Equalization enhanced phase noise; frequency noise; coherent optical communications; carrier phase recovery; carrier phase estimation; circular quadrature amplitude modulation; EEPN; CmQAM; blind phase search; phase noise;

    Sammanfattning : The increase in capacity demand along with the advancement in digital signal processing (DSP) have recently revived the interest in coherent optical communications and led to its commercialization. However, design and development of robust DSP algorithms for example for carrier phase recovery (CPR) becomes complex as we opt for high order modulation formats such as 16QAM and beyond. LÄS MER

  4. 18. Mid-infrared photonic devices for on-chip optical gas sensing

    Författare :Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mid-infrared; mid-IR; photonics; silicon photonics; gas sensing; optical sensing; optical gas sensing; spectroscopy; absorption; dispersion; carbon dioxide; CO2; CO2 sensing; trace gas; ethanol sensing; alcohol sensing; waveguide; photonic waveguide; ring resonator; nanowire; nanoheater; emitter; thermal source; bolometer; microbolometer; thermal detector; high frequency; 3 omega method; plasmonic; platinum; Kanthal; silicon-on-insulator; micro-electro-mechanical systems MEMS ; microfabrication; microsystems; microtechnology; nanotechnology; Optik och fotonik; Optics and Photonics; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. LÄS MER

  5. 19. Optical Coherence Tomography for Dermatological Applications

    Författare :Jakob Borup Thomsen; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; medical imaging; skin cancer diagnostics; optical imaging; blood flow; treatment monitoring;

    Sammanfattning : Optical coherence tomography (OCT) is a non-invasive optical imaging technique providing approximately 10 micrometer resolution of tissue in vivo. Within ophthalmology, OCT has already proven its value and is routinely used for diagnosing retinal diseases. LÄS MER

  7. 20. Optical Investigations of Chiral Liquid Crystals

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

    Sammanfattning : 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. LÄS MER