Amorphous silicon optical waveguides and Bragg mirrors

A. Khanna*, M. Mulot, S. Arpiainen, A. Säynätjoki, J. Ahopelto, S. Honkanen, H. Lipsanen

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

    12 Citations (Scopus)


    We study 200 nm thick hydrogenated amorphous silicon (a-Si:H) optical strip waveguides fabricated by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique over PECVD silicon oxide on top of standard silicon wafer. The layer of a-Si:H is etched by Reactive Ion Etching (RIE). The ability to deposit a-Si:H at low temperatures (~250°C) by PECVD renders it a promising material for integration of optical waveguides with microelectronics. Waveguides with width varying from 2 μm to 10 μm exhibit low loss. Material refractive index data of a-Si:H is measured by reflectometry and is used in simulations. A high refractive index contrast between a-Si:H and air allows tight optical confinement of modes. We demonstrate Bragg gratings fabricated by e-beam writing technology on top of the waveguides. The period of the grating is approximately 300 nm and the depth of the grooves is about 30 nm. The grating on top of the waveguide act as mirror.

    Original languageEnglish
    Title of host publicationSilicon Photonics and Photonic Integrated Circuits
    EditorsGC Righini, SK Honkanen, L Pavesi, L Vivien
    Number of pages9
    ISBN (Print)9780819471949
    Publication statusPublished - 2008
    MoE publication typeA4 Conference publication
    EventSilicon Photonics and Photonic Integrated Circuits - Strasbourg, France
    Duration: 7 Apr 200810 Apr 2008

    Publication series

    NameProceedings of SPIE
    ISSN (Print)0277-786X


    ConferenceSilicon Photonics and Photonic Integrated Circuits


    • Amorphous silicon
    • Bragg mirror
    • Propagation loss
    • Strip waveguide


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