Sökning: "surface relief"

Visar resultat 1 - 5 av 41 avhandlingar innehållade orden surface relief.

  1. 1. Mode and Polarization Control in VCSELs using Surface Structures

    Författare :Åsa Haglund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single mode; dynamics; surface relief; Semiconductor laser; polarization; vertical-cavity surface-emitting laser; sub-wavelength grating; fabrication;

    Sammanfattning : The vertical-cavity surface-emitting laser (VCSEL) is a novel, low-cost light source with many attractive performance characteristics, such as low operating current, circular output beam, and high modulation bandwidth at low currents. This together with its easy integration into two-dimensional arrays has made it an established transmitter in short-distance single and parallel fiber-optical links, and new applications are continuously arising. LÄS MER

  3. 2. Vertical Cavity Surface Emitting Lasers for Access Network Applications

    Författare :Emma Söderberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; highly strained InGaAs; single mode emission; Vertical Cavity Surface Emitting Lasers VCSELs ; inverted surface relief; high speed modulation;

    Sammanfattning : .... LÄS MER

  4. 3. Manufacture of High Efficiency Surface Relief Computer Generated Holograms

    Författare :Mats Ekberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kinoforms; ;

    Sammanfattning : This thesis treats design, manufacture, evaluation and applications of computer-generated surface relief holograms - kinoforms. These diffractive, phase-only, planar optical components are characterized by high efficiency, design flexibility, light weight and small size. They can further be reproduced at low cost. LÄS MER

  5. 4. Effect of Stress Relief Annealing: Part Distortion, Mechanical Properties, and Microstructure of Additively Manufactured Austenitic Stainless Steel

    Författare :Emil Edin; Marta-Lena Antti; Pia Åkerfeldt; Fredrik Svahn; Magnus Neikter; Paul Åkerström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser powder bed fusion; stainless steel; residual stress; heat treatment; tensile testing; relaxation testing; Materialteknik; Engineering Materials;

    Sammanfattning : Additive manufacturing (AM) processes may introduce large residual stresses in the as-built part, in particular the laser powder bed fusion process (L-PBF). The residual stress state is an inherent consequence of the heterogeneous heating and subsequent cooling during the process. LÄS MER

  7. 5. Modal Dynamics of Vertical-Cavity Surface-Emitting Lasers

    Författare :Johan Gustavsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transverse modes; noise; modeling; Semiconductor laser; dynamics; vertical-cavity surface-emitting laser;

    Sammanfattning : In this work, a comprehensive dynamic model has been developed for simulating a novel semiconductor laser type, referred to as the Vertical-Cavity Surface-Emitting Laser (VCSEL). The high-speed behavior was simulated and compared to experiments, where excellent agreement was found. LÄS MER