Laser Structures with Semipolar Quantum Wells Grown by Selective Area Epitaxy

Using selective area epitaxy to produce three-dimensional GaN structures, two different concepts for laser diodes (LDs) with semipolar quantum wells (QWs) are developed, each having distinct advantages and disadvantages. The first approach utilizes a stripe with triangular cross-section not only to grow semipolar quantum wells on, but also as waveguide and resonator cavity. Based on simulations of modal characteristics we develope the epitaxial structure and address the difficulties of selective growth of the aluminum containing layers. The second approach integrates the three-dimensional structures with semipolar sidefacets into a conventional LD design with planar cladding layers. Therefore we miniaturize the selectively grown stripes to a submicrometer scale, positioning the active layer with semipolar QWs inside the core of a planar waveguide. For both approaches we present experimental results, regarding structural as well as optical properties including SEM, CL, PL, TEM and gain measurements.