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Publication - Professor Judy Rorison

    Optical gain in GaAsBi/GaAs quantum well diode lasers


    Marko, IP, Broderick, CA, Jin, S, Ludewig, P, Stolz, W, Volz, K, Rorison, J, O’Reilly, EP & Sweeney, SJ, 2016, ‘Optical gain in GaAsBi/GaAs quantum well diode lasers’. Scientific Reports, vol 6.


    Electrically pumped GaAsBi/GaAs quantum well lasers are a promising new
    class of near-infrared devices where, by use of the unusual band
    structure properties of GaAsBi alloys, it is possible to suppress the
    dominant energy-consuming Auger recombination and inter-valence band
    absorption loss mechanisms, which greatly impact upon the device
    performance. Suppression of these loss mechanisms promises to lead to
    highly efficient, uncooled operation of telecommunications lasers,
    making GaAsBi system a strong candidate for the development of
    next-generation semiconductor lasers. In this report we present the
    first experimentally measured optical gain, absorption and spontaneous
    emission spectra for GaAsBi-based quantum well laser structures. We
    determine internal optical losses of 10–15 cm−1 and a peak modal gain of 24 cm−1, corresponding to a material gain of approximately 1500 cm−1 at a current density of 2 kA cm−2.
    To complement the experimental studies, a theoretical analysis of the
    spontaneous emission and optical gain spectra is presented, using a
    model based upon a 12-band k.p Hamiltonian for GaAsBi alloys. The
    results of our theoretical calculations are in excellent quantitative
    agreement with the experimental data, and together provide a powerful
    predictive capability for use in the design and optimisation of high
    efficiency lasers in the infrared.

    Full details in the University publications repository