Reliable low-cost fabrication of low-loss Al2O3:Er3+ waveguides with 5.4-dB optical gain

R.J. Lang (Editor), Kerstin Worhoff, J. Bradley, F. Ay, D. Geskus, Tom P. Blauwendraat, Markus Pollnau

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    A reliable and reproducible deposition process for the fabrication of $Al_2O_3$ waveguides with losses as low as 0.1 dB/cm has been developed. The thin films are grown at ~ 5 nm/min deposition rate and exhibit excellent thickness uniformity within 1% over 50times50 mm2 area and no detectable $OH^{-}$ incorporation. For applications of the $Al_2O_3$ films in compact, integrated optical devices, a high-quality channel waveguide fabrication process is utilized. Planar and channel propagation losses as low as 0.1 and 0.2 dB/cm, respectively, are demonstrated. For the development of active integrated optical functions, the implementation of rare-earth-ion doping is investigated by cosputtering of erbium during the $Al_2O_3$ layer growth. Dopant levels between 0.2-5times $1020 cm^{-3}$ are studied. At $Er^{3+}$ concentrations of interest for optical amplification, a lifetime of the 4I13/2 level as long as 7 ms is measured. Gain measurements over 6.4-cm propagation length in a 700-nm-thick $Al_2O_3:Er^{3+}$ channel waveguide result in net optical gain over a 41-nm-wide wavelength range between 1526-1567 nm with a maximum of 5.4 dB at 1533 nm
    Original languageUndefined
    Article number10.1109/JQE.2009.2013365
    Pages (from-to)454-461
    Number of pages8
    JournalIEEE journal of quantum electronics
    Issue number5
    Publication statusPublished - 5 May 2009


    • EC Grant Agreement nr.: FP6/017501
    • reactive co-sputtering
    • low-loss dielectric waveguide
    • optical amplifier
    • Erbium
    • Integrated Optics
    • IOMS-APD: Active Photonic Devices
    • Aluminium oxide
    • IR-67472
    • METIS-263846
    • EWI-15357

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