Strain compensation techniques for red AlGalnP-VECSELs:Performance comparison of epitaxial designs

摘要

We present a strain-compensation design for non-resonantly pumped vertical external cavity surface-emitting lasers for emission in the red spectral range around 665 nm. Here, the VECSEL chip is based on a metal-organic vapor-phase epitaxy grown (Ga_xIn_(1_x))_(0.5)P_(0.5)/[(.Al_xGa_(1_x))_yIn_(1-y)]_(0.50P_(0.5) multi-quantum-well structure with 20 compressively strained quantum wells. By introducing tensile strained quaternary barriers and cladding layers in a 5 × 4 QW design, we could compensate for the compressive strain introduced by the quantum wells. Photoluminenscence measurements of structures with different numbers of quantum well packages reveal a more homogenous quantum well growth due to the strain-compensation technique. Furthermore, with the strain compensation technique, the output power could be increased over 30% compared to our conventional structures.