Sökning: "slab waveguide"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden slab waveguide.

  1. 1. Designs and simulations of silicon-based microphotonic devices

    Författare :Daoxin Dai; Sailing He; Siegfried Janz; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; waveguide; silicon-on-insulator SOI ; arrayed waveguide grating AWG ; Elektronik; Electronics; Elektronik;

    Sammanfattning : The characteristics of a silicon-on-insulator (SOI) rib waveguide, including the bending loss of a multimode bent waveguide and the birefringence of a rib waveguide, are analyzed by using a finite-difference method (FDM). Based on a detailed analysis for a multimode bent waveguide, an appropriately designed multimode bent waveguide for reducing effectively the bending loss of the fundamental mode is realized. LÄS MER

  3. 2. Simulating rolling noise on ballasted and slab tracks: vibration, radiation, and pass-by signals

    Författare :Jannik Theyssen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway rolling noise; Numerical modelling; Green s functions; Time domain; Spherical harmonics; Slab track; 2.5D FE BE;

    Sammanfattning : Shifting to rail-bound freight and passenger traffic is key in Europe's strategy towards transport decarbonisation. However, increasing railway traffic can increase environmental noise pollution. Rolling noise is often the dominant noise source. It originates from the interaction of the rough running surfaces of wheel and rail. LÄS MER

  4. 3. Design, Fabrication, and Characterization of Nano-Photonic Components Based on Silicon and Plasmonic Material

    Författare :Liu Liu; Lars Thylén; Roe Baets; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nano-photonics; finite-difference time-domain method; finite-difference mode solver; amorphous silicon; silicon nanowire; arrayed waveguide grating; photonic crystal; Photonics; Fotonik;

    Sammanfattning : Size reduction is a key issue in the development of contemporary integrated photonics. This thesis is mainly devoted to study some integrated photonic components in sub-wavelength or nanometric scales, both theoretically and experimentally. LÄS MER

  5. 4. Dispersion Engineering : Negative Refraction and Designed Surface Plasmons in Periodic Structures

    Författare :Zhichao Ruan; Min Qiu; Henri Benisty; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photonic crystal; dispersion property; negative refraction; surface plasmon polariton; designed surface plasmon; negative index material; layer-KKR method; finite-difference time-domain method; plane wave method; subwavelength imaging; open cavity; enhanced transmission; slowing light; Photonics; Fotonik;

    Sammanfattning : The dispersion property of periodic structures is a hot research topic in the last decade. By exploiting dispersion properties, one can manipulate the propagation of electromagnetic waves, and produce effects that do not exist in conventional materials. LÄS MER

  7. 5. Transient Electromagnetic Waves in Nonlinear Media

    Författare :Daniel Sjöberg; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; nonlinear materials; Electromagnetic waves; instantaneous response; waveguides; shock waves; entropy condition; Elektronik och elektroteknik; Electronics and Electrical technology; Signalbehandling; Electromagnetism; optics; acoustics; Elektromagnetism; optik; akustik;

    Sammanfattning : This thesis is concerned with the propagation of transient electromagnetic waves in nonlinear media. It consists of a General Introduction and five scientific papers. The General Introduction gives a broad overview of nonlinear electromagnetic phenomena. LÄS MER