Sökning: "grating structures"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden grating structures.

  1. 1. Electromagnetic simulation and design of etched diffraction grating demultiplexers

    Författare :Jun Song; Sailing He; Dries Van Thourhout; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; etched diffraction grating; wavelength division multiplexing; passive devices; diffraction grating; planar waveguide devices; DWDM; optical communication.; Photonics; Fotonik;

    Sammanfattning : Among various planar lightwave circuits for multiplexing/demultiplexing in an optical communication system, etched diffraction gratings (EDGs) have shown great potential due to their compactness and high spectral finesse. Conventional numerical methods for grating simulation cannot be used to simulate an EDG demultiplexer of large size (in terms of the wavelength). LÄS MER

  3. 2. Photonic devices with MQW active material and waveguide gratings : modelling and characterisation

    Författare :Nadeem Akram; Lars Thylén; Hartmut Hillmer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Method of Lines; Grating; ARROW Waveguide; Semiconductor laser; quantum well; Photonics; Fotonik;

    Sammanfattning : The research work presented in this thesis deals with modelling, design and characterisation of passive and active optical waveguide devices. The rst part of the thesis is related to algorithm development and numerical modelling of planar optical waveguides and gratings using the Method of Lines (MoL). LÄS MER

  4. 3. 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

  5. 4. Multifunctional Waveguide Grating Couplers for Integrated Optics

    Författare :Johan Backlund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis describes a novel waveguide component in integrated optics called a multifunctional grating coupler. It couples light in or out of optical waveguides and provides additional optical functions such as beam splitting, arbitrary focusing, polarization sensing, and wavelength separation (wavelength division demultiplexing). LÄS MER

  7. 5. Wafer-scale Vacuum and Liquid Packaging Concepts for an Optical Thin-film Gas Sensor

    Författare :Mikael Antelius; Göran Stemme; Yogesh B. Gianchandani; KTH; []
    Nyckelord :Microelectromechanical systems; MEMS; Nanoelectromechanical systems; NEMS; silicon; wafer-level; packaging; vacuum packaging; liquid encapsulation; integration; wire bonding; grating coupler; waveguide; Fabry-Perot resonator;

    Sammanfattning : This thesis treats the development of packaging and integration methods for the cost-efficient encapsulation and packaging of microelectromechanical (MEMS) devices. The packaging of MEMS devices is often more costly than the device itself, partly because the packaging can be crucial for the performance of the device. LÄS MER