High-efficiency InP SWIR VCSELs enabled by a mass-producible nanoporous DBR

We present high-efficiency short-wave infrared (SWIR) InP VCSELs enabled by a cost-effective bottom DBR and simple aperture formation techniques. A homoepitaxially grown InP bottom DBR was transformed into a nanoporous (NP) DBR with a high index contrast (Δn ~1.0) using a conductivity-selective electrochemical etching process, enabling a thin bottom DBR sufficient for high-efficiency VCSEL demonstration. The current and optical apertures were defined by proton implantation and shallow surface relief, respectively. Continuous-wave (CW) operation at 1.38μm was demonstrated, achieving a peak power conversion efficiency of nearly 30% and a differential quantum efficiency above 52%. This approach was further extended to top-emitting VCSEL arrays, which showed no noticeable performance degradation.