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