Sökning: "long-wavelength"

Visar resultat 11 - 15 av 46 avhandlingar innehållade ordet long-wavelength.

  1. 11. Design and fabrication of multiple quantum well structures for long wavelength laser diodes

    Författare :Christofer Silfvenius; KTH; []
    Nyckelord :;

    Sammanfattning : InGaAsP multiple quantum well (MQW) structures emitting at1300 nm have been designed, fabricated with metal organicvapour phase epitaxy (MOVPE) and evaluated by x-ray diffraction(XRD), photoluminescence (PL) and by laser characterisation. Inaddition the structures were subject to scanning probemicroscopy (STM/AFM) and direct carrier transport measurements. LÄS MER

  3. 12. Infrared Emittance of Paper : Method Development, Measurements and Application

    Författare :Caroline Hyll; Lars Mattsson; Hannes Vomhoff; Carl-Gustaf Ribbing; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Emittance; Emissivity; Thermography; Paper; Sheet; Papermaking; Paper mechanics; Moisture; Material properties; Reflectance; Transmittance; Absorptance; Infrared; Mid-wavelength infrared; MWIR; Long-wavelength infrared; LWIR; Angle-resolved; Directional;

    Sammanfattning : Thermography is a non-destructive technique which uses infrared radiation to obtain the temperature distribution of an object. The technique is increasingly used in the pulp and paper industry. To convert the detected infrared radiation to a temperature, the emittance of the material must be known. LÄS MER

  4. 13. Epitaxial growth optimization for 1.3-um InGaAs/GaAs Vertical-Cavity Surface-Emitting lasers

    Författare :Zhenzhong Zhang; Mattias Hammar; Nicolae Chitica; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; VCSEL MOVPE InGaAs GaAs quantum wells; Semiconductor physics; Halvledarfysik;

    Sammanfattning : Long-wavelength (1.3-μm) vertical-cavity surface-emitting lasers (VCSELs) are of great interest as low-cost, high performance light sources for fiber-optic metro and access networks. During recent years the main development effort in this field has been directed towards all epitaxial GaAs-based structures by employing novel active materials. LÄS MER

  5. 14. The use of fluorescence techniques for the study of some membrane-bound photosynthetic properties and some effects of copper on the thylakoid membrane

    Författare :Göran Samuelsson; N. Valanne; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chlorophylI-protein complexes; sequential extraction; ß-carotene low temperature fluorescence emission; absorption; in vivo chi. a fluorescence; copper; electron transport;

    Sammanfattning : Lyophilized pea chloroplasts were extracted in a stepwise manner in an organic solvent (petroleum ether) with increasing polarity which was obtained by addition of small amount of ETOH (0-1 %). Absorption and low temperature fluorescence emission spectra were measured on both the extracted thylakoids and on isolated chlorophylI-protein complexes. LÄS MER

  7. 15. Development of 1.3-μm GaAs-based vertical-cavity surface-emitting lasers

    Författare :Petrus Sundgren; Mattias Hammar; Harri Lipsanen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik;

    Sammanfattning : Long-wavelength vertical-cavity surface-emitting lasers (VCSELs) are desirable as low-cost sources for optical metropolitan-area and access networks. In the development of 1.3-µm VCSELs, most attention today is given to monolithic GaAs-based solutions, although no established active material exists in this wavelength region. LÄS MER