Energy-transfer upconversion in Al2O3:Er3+ thin layers

Kerstin Worhoff, J. Bradley, L. Agazzi, D. Geskus, F. Ay, A. Kahn, H. Scheife, K. Petermann, G. Huber, Markus Pollnau

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    Erbium-doped aluminum oxide (Al2O3:Er) is a promising material for integrated amplifier or tunable laser applications due to its wide gain spectrum around 1550 nm. We deposited Al2O3 layers on thermally oxidized Si-wafers by reactive co-sputtering at 550°C. Propagation losses were 0.11 dB/cm at λ =1.5 μm. Channel waveguides were fabricated by reactive ion etching with propagation losses down to 0.21 dB/cm. Under pumping at 977 nm, the optical small-signal gain at 1533 nm is 0.84 dB/cm, resulting in 5.4 dB net gain over the waveguide length of 6.4 cm. Net gain is obtained over a wavelength range of 41 nm. The Er concentration was measured using Rutherford Back-Scattering (RBS). Lifetimes of the 4I13/2 level of up to 7 ms were measured for Er concentrations around 2×1020 cm-3. A faster decay with an increasingly non-exponential initial component is measured for higher Er concentrations (Fig. 2). While the initial quenching is probably due to migration-accelerated energy-transfer upconversion between neighboring Er3+ ions in the 4I13/2 level, the decreasing exponential tail is due to either pair-induced energy-transfer upconversion or quenching by impurity ions. Detailed investigations of the quenching mechanisms are currently under way.
    Original languageUndefined
    Title of host publicationSecond International Workshop on Advanced Spectroscopy and Optical Materials
    Place of PublicationGdansk, Poland
    PublisherGdansk University
    PagesPaper 6-O
    Number of pages1
    ISBN (Print)not assigned
    Publication statusPublished - Jul 2008
    EventSecond International Workshop on Advanced Spectroscopy and Optical Materials - Gdansk, Poland
    Duration: 13 Jul 200817 Jul 2008

    Publication series

    PublisherInstitute of Experimental Physics, Gdansk University


    WorkshopSecond International Workshop on Advanced Spectroscopy and Optical Materials
    Other13-17 July 2008


    • IOMS-APD: Active Photonic Devices
    • METIS-255118
    • IR-65296
    • EWI-14872

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