Infrared nBn detectors monolithically integrated with metasurface-based optical concentrators

We demonstrate InAsSb-based infrared photodetectors monolithically integrated with metasurface lenses (metalenses) that act as optical concentrators. The metalenses are fabricated on the backside of a gallium antimonide substrate, and the photodetectors are fabricated on the frontside of the same substrate. The metalenses enhance the detector responsivity up to 10-fold and detectors retain the same detectivity at temperatures up to 40 K higher. Detectors integrated with metalenses exhibit detectivities greater than D* = 10(10) cm root Hz / W at lambda = 3.75 mu m up to room temperature. Our metasurface-based optical concentrators are based on circular subwavelength nanoposts, which renders their performance polarization independent.

Automated summary

This article demonstrates the monolithic integration of InAsSb-based infrared photodetectors with metasurface lenses, which act as optical concentrators. The metalenses, based on circular subwavelength nanoposts, can enhance detector responsivity and maintain performance at high temperatures. Detectors integrated with metalenses exhibit high detectivities up to room temperature.