Sökning: "Optik och fotonik"

Visar resultat 26 - 30 av 43 avhandlingar innehållade orden Optik och fotonik.

  1. 26. Fabrication and Characterization of Plasmonic Nanophotonic Absorbers and Waveguides

    Författare :Yiting Chen; Min Qiu; Min Yan; Francisco Javier García de Abajo; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nanophotonics; plasmonics; fabrication; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Sammanfattning : Plasmonics is a promising field of nanophotonics dealing with light interaction with metallic nanostructures. In such material systems, hybridizationof photons and collective free-electron oscillation can result in sub-wavelength light confinement. LÄS MER

  3. 27. Carrier dynamics in blue and green InGaN LED structures

    Författare :Rinat Yapparov; Saulius Marcinkevičius; Ulrich Theodor Schwarz; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; InGaN quantum wells; interwell transport; near-field scanning optical microscopy; internal quantum efficiency; V-defects; InGaN-kvantbrunnar; transport mellan brunnar; optisk mikroskopi med närafältsskanning; intern kvanteffektivitet; V-defekter; Physics; Fysik; Optics and Photonics; Optik och fotonik;

    Sammanfattning : This thesis focuses on effects that are critical to achieving high internal quantum efficiency (IQE) in GaN-based light-emitting diodes (LEDs) that emit in a broad spectral range, from violet to green-yellow. These effects include interwell carrier transport in multiple quantum well (QW) structures, lateral transport in the QW plane, and radiative and nonradiative recombination. LÄS MER

  4. 28. Metal-assisted chemical etching for nanofabrication of hard X-ray zone plates

    Författare :Rabia Akan; Ulrich Vogt; Muhammet Toprak; Carmen Vogt; Lucia Romano; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; metal-assisted chemical etching; zone plate; high-aspect ratio; silicon; nanostructures; Material and Nano Physics; Material- och nanofysik; Optik och fotonik; Optics and Photonics;

    Sammanfattning : Hard X-ray scanning microscopes, or nanoprobes, make it possible to image samples and probe their chemical, elemental and structural properties at nanoscale resolution. This is enabled by the use of nanofocusing optics. Commonly used optics in nanoprobes for high resolution X-ray experiments are zone plates. LÄS MER

  5. 29. Luminescent Silicon Nanocrystals: From Single Quantum Dot to Light-harvesting Devices

    Författare :Jingjian Zhou; Ilya Sychugov; Jan Linnros; Peter Schall; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; silicon quantum dots; photoluminescence; quantum yield; internal quantum efficiency; luminescent solar concentrator; Optics and Photonics; Optik och fotonik;

    Sammanfattning :       Silicon (Si) serves as the basic material of the system-on-a-chip industry and photovoltaic panels nowadays. This is mostly thanks to its high abundance in the earth’s crust, thereby low cost, virtually non-toxicity, and superior stability. LÄS MER

  7. 30. Additive manufacturing of fused silica glass

    Författare :Pawel Maniewski; Michael Fokine; Fredrik Laurell; Daniel Milanese; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laser cladding; 3d printing; additive manufacturing; glass; fused silica; laser; scattering; silica; Optik och fotonik; Optics and Photonics; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : Additive Manufacturing, of both metals and polymers, has seen rapid development in recent years, whereas the progress in glass has been rather slow. Today, glass can be considered the last frontier without a specialized 3D printing method available. LÄS MER