Three Dimensional Nanopillar Optical Antenna Avalanche Detectors

Avalanche photodetectors APDs operating at 1064 nm are an integral component of light detection and ranging LiDAR systems used in imaging technologies such as acquisition tracking and pointing ATP and airborne topographic mapping. Current state-of-the-art APDs utilize a separate absorption-multiplication SAM structure using an In0.53Ga0.47As absorber lattice-matched to an InP multiplication layer. When operated in Geiger mode, these detectors are limited by the dark count rate caused by generation current in the InGaAs, making low-temperature operation necessary. At low temperature, trap-assisted tunneling TAT in the InP limits the performance. Although in theory it is possible to reduce generation current in the InGaAs by reducing the indium fraction while still effectively absorbing at 1064nm, in practice the reduction of bulk generation current is offset by the poor material quality resulting from lattice mismatched growth on InP.