Sökning: "Optical physics"

Visar resultat 1 - 5 av 559 avhandlingar innehållade orden Optical physics.

  1. 1. Optical Studies and Applications of Single Quantum Dots

    Författare :Valéry Zwiller; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; time resolved photoluminescence; Physics; Fysik; Semiconductory physics; Halvledarfysik; Condensed matter:electronic structure; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; spektroskopi; magnetisk resonans; microphotoluminescence; microcavities; photoluminescence; quantum optics; nano-optics; photonics; low dimensional structures; quantum dots; Fysicumarkivet A:2001:Zwiller;

    Sammanfattning : The luminescence from single quantum dots has been studied. Single dot photoluminescence was studied under continuous as well as under pulsed excitation. Time-resolved studies revealed fast relaxations in quantum dots. The time resolved measurements were fitted with a set of rate equations. LÄS MER

  2. 2. Optical parametric amplification with periodically poled KTiOPO4

    Författare :Anna Fragemann; Fredrik Laurell; Ebrahim-Zadeh Majid; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; optical parametric amplification; optical parametric generation; optical parametric oscillation; Optical physics; Optisk fysik;

    Sammanfattning : This thesis explores the use of engineered nonlinear crystals from the KTiOPO4 (KTP) family as the gain material in optical parametric amplifiers (OPAs), with the aim to achieve more knowledge about the benefits and limitations of these devices. The work aims further at extending the possible applications of OPAs by constructing and investigating several efficient and well performing amplifiers. LÄS MER

  3. 3. Optical Analysis of biological media - continuous wave diffuse spectroscopy

    Författare :Jan Sørensen Dam; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spatially resolved diffuse reflectance; in vitro diffuse spectroscopy; continuous wave techniques; Nuclear physics; multivariate data analysis.; Kärnfysik; Fysik; Physics; Medicin människa och djur ; Medicine human and vertebrates ; Monte Carlo simulations; light propagation models; multiple scattering; Tissue optics; tissue optical properties; Fysicumarkivet A:2000:Sörensen Dam;

    Sammanfattning : The main topic of this thesis is real-time quantification of relevant chromophores and light scattering elements in biological media. The presented methods and instrumentation are based on continuous wave (steady-state) optical measurements of (a) spatially-resolved diffuse reflectance from bulk media and (b) combined spatially-resolved and goniometric measurements of re-emitted light from thin samples. LÄS MER

  4. 4. Photonic MEMS for optical information technologies

    Författare :Carlos Errando-Herranz; Kristinn B. Gylfason; Wolfram Pernice; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Micro-electro-mechanical systems MEMS ; photonics; silicon photonics; photonic integrated circuits PIC ; lithium niobate photonics; ring resonator; polarization beam splitter PBS ; microfluidic integration; lab-on-chip LoC ; optical beam steering; nonlinear optics; Electrical Engineering; Elektro- och systemteknik; Physics; Fysik; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Photonic integrated circuits (PICs) combine hundreds of optical components on a chip, and can enable fast communications, high-performance computing, and improved sensing. PICs, made by miniaturized optical waveguides, require many reconfigurable elements to enable programmable functionalities and to compensate for fabrication variations and environmental factors. LÄS MER

  5. 5. Optical spectroscopy of InGaAs quantum dots

    Författare :Arvid Larsson; Per Olof Holtz; Artur Zrenner; Linköpings universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; quantum dot; semiconductor; optical properties; spin; transport; wetting layer; polarization; kvantprick; halvledare; optiska egenskaper; spin; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Materials science; Teknisk materialvetenskap; Condensed matter physics; Kondenserade materiens fysik; Semiconductor physics; Halvledarfysik;

    Sammanfattning : The work presented in this thesis deals with optical studies of semiconductor quantum dots (QDs) in the InGaAs material system. It is shown that for self-assembled InAs QDs, the interaction with the surrounding GaAs barrier and the InAs wetting layer (WL) in particular, has a very large impact on their optical properties. LÄS MER