Sökning: "upconversion"

Visar resultat 1 - 5 av 37 avhandlingar innehållade ordet upconversion.

  1. 1. Advancing Upconversion Emissions for Biomedical Imaging

    Författare :Haichun Liu; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; upconverting nanoparticles; luminescence; fluorescence; inverse problem; biomedical optics; biomedical imaging; photon migration; upconversion; tomography; saturation; Fysicumarkivet A:2014:Liu;

    Sammanfattning : During the past decade, upconverting nanoparticles (UCNPs) doped with rare earth ions have become an important class of fluorescence contrast agents for molecular imaging, due to their unique properties. Their property of anti-Stokes luminescence, with both the excitation and emission wavelengths close to the optimal for biomedical imaging, has been extensively explored in various biomedical applications. LÄS MER

  3. 2. Upconversion Detection for Improved Nonlinear Mid-infrared Spectroscopy in Flames

    Författare :Rasmus Lyngbye Pedersen; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; infrared; upconversion; degenerate four wave mixing; hydrogen cyanide; polarisation spectroscopy;

    Sammanfattning : This thesis deals with the addition of upconversion detection to non-linear mid-infrared laser spectroscopy techniques. The techniques investigated here are degenerate four wave mixing (DFWM) and infrared polarization spectroscopy (IRPS). LÄS MER

  4. 3. Photon Upconversion in Heavily Doped Semiconductors

    Författare :Kilian Mergenthaler; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; III-V semiconductor materials; nanowires; photoluminescence; Photon upconversion; semiconductors; doping; Fysicumarkivet A:2016:Mergenthaler;

    Sammanfattning : In this thesis the luminescence properties of highly doped semiconductors are studied with focus on degenerately n-doped InP. It is demonstrated how photoluminescence measurements on degenerately doped semiconductors allow an estimation of the doping concentration without need for electrical contacts. LÄS MER

  5. 4. Upconversion in Er doped silica : - characterization and modeling

    Författare :Dmitry Khoptyar; Bozena Jaskorszynska; Anders Bjarklev; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : Further increase of erbium concentrations in Er-doped amplifiers and lasers is needed for the design of efficient, reliable, compact and cost-effective components for telecommunications and other photonic applications. However, this is hindered by Er concentration dependent loss mechanism known as upconversion. LÄS MER

  7. 5. Intramolecular Electronic Interactions in Photon Upconversion and Singlet Fission

    Författare :Fredrik Edhborg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Singlet Fission; Photon Upconversion; Intramolecular; Excitation Energy Transfer; Solar Energy Conversion;

    Sammanfattning : The sun provides our planet with an abundance of energy in the form of solar light – a continuous stream of photons. Increasing our direct utilization of solar energy will constitute a necessary part in our ongoing replacement of fossil fuels with energy sources free from greenhouse gas emissions. LÄS MER