A systematic design of a GaN/AlGaN active region for a three-level intersubband laser emitting in the near-infrared is presented. The proposed system is based on a double coupled quantum well structure with the laser level energy separation corresponding to 1.55 μm (Δe32 ∼ 800 meV), a wavelength important for optical communications. The lower laser level depopulates mostly via longitudinal optical phonon resonance, requiring Δe21 ∼ 90meV. The model for scattering rate calculations, including many-body carrier screening effects, was first tested by comparison with recent experimental measurements in GaN/AlGaN quantum wells, and a very good agreement was obtained. It was then employed to calculate the gain coefficient, a commonly used figure of merit for three level laser systems, and this in turn allowed the optimal structural parameters of GaN/AlGaN quantum well to be found.
|Number of pages
|Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
|Published - 1 Nov 2004