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

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 (GaxIn1−x)0.5P0.5/[(AlxGa1−x)yIn 1−y]0.5P0.5 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.

► AlGaInP-VECSELs are fabricated by metal-organic vapor-phase epitaxy with different designs.
► Strain-compensation is accomplished with tensile strained barriers/cladding layers.
► X-ray diffraction scans show tensile behavior with an (Al,Ga) content of ∼52%∼52%.
► Strain-compensated active regions show more homogenous QW growth with reduced linewidths.
► Strain-compensated VECSEL chips have increased absorption efficiency and higher output power.