Rare-earth-ion-doped Al2O3 waveguides for active integrated optical devices

J. Bradley, F. Ay, Tom Blauwendraat, Kerstin Worhoff, Markus Pollnau

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

    1 Citation (Scopus)


    Reactively co-sputtered amorphous $Al_2O_3$ waveguide layers with low propagation losses have been deposited. In order to define channel waveguides in such $Al_2O_3$ films, the etching behaviour of $Al_2O_3$ has been investigated using an inductively coupled reactive ion etch system. The etch rate of $Al_2O_3$ and possible mask materials was studied by applying various common process gases and combinations of these gases, including $CF_4/O_2, BCl_3, BCl_3/HBr$ and $Cl_2$. Based on a comparison of the etch rates and patterning feasibility of the different mask materials, a $BCl_3/HBr$ plasma and and standard resist mask were used to fabricate channel waveguide structures. The etched structures exhibit straight sidewalls with minimal roughness and etch depths of up to 530 nm, sufficient for defining waveguides with strong optical confinement and low bending losses. Low additional propagation losses were measured in single-mode $Al_2O_3$ ridge waveguides defined using the developed etch process. In initial investigations, $Al_2O_3:Er$ layers fabricated using the same deposition method applied for the undoped layers show typical emission cross-sections, low green upconversion luminescence and lifetimes up to 7 ms.
    Original languageUndefined
    Title of host publicationProceedings International Conference on Lasers, Applications, and Technologies 2007: Advanced Lasers and Systems
    EditorsValentin A. Orlovic, Vladislav Panchenko, Ivan A. Scherbakov
    Place of PublicationBellingham, Washington, U.S.A.
    PublisherSPIE International
    Number of pages8
    Publication statusPublished - 9 Aug 2007

    Publication series

    NameProceedings of SPIE
    PublisherSPIE International
    ISSN (Print)0277-786X


    • IOMS-APD: Advanced Photonic Devices
    • IR-62073
    • METIS-245881
    • EWI-11615
    • EC Grant Agreement nr.: FP6/017501

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