Sökning: "near-field imaging"
Visar resultat 1 - 5 av 13 avhandlingar innehållade orden near-field imaging.
1. Photonic terahertz-wave generation, radiation and quasioptical integration
Sammanfattning : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. LÄS MER
2. Single layer near-field acoustic imaging in space-invariant reflective environments
Sammanfattning : The visualization of optical fields, or widely known as photography, is a common practice that can also be applied to acoustic fields. No less than three decades of research in acoustic imaging demonstrate its potential and relevance in plenty applications such as sound source identification and localization, as well as characterization of noise generation mechanisms. LÄS MER
3. Measurement and evaluation of near-field spray kinematics for nozzles with asymmetrical inlet geometries
Sammanfattning : In diesel engines, fuel injection parameters have a commanding effect on mixing and combustion quality. This research aims to enhance the fundamental knowledge of fuel sprays and their primary break-up. In addition, this research provides statistical data to validate simulation models and improve the prediction accuracy in mixing and combustion. LÄS MER
4. Optical Imaging and Spectroscopy of Metal Nanostructures
Sammanfattning : Noble metal structures with size in the sub 100 nm range exhibit extraordinary optical properties due to collective oscillations of conduction electrons, the surface plasmon resonances (SPR). The most remarkable feature of these structures is the ability to redistribute electromagnetic radiation and concentrate strong fields near the surface. LÄS MER
5. Design of Functional Structures and Measurement Techniques for Electromagnetic Waves
Sammanfattning : Electromagnetic fields exist all around us. Through evolution, nature has developed tools to interact and use these fields, where our eyes are a spectacular example. Humans have a long history of developing structures and objects of their own to alter and interact with these fields. LÄS MER