Enhanced Photon Number Resolving Detection with High-Efficient InGaAs/InAlAs Single Photon Avalanche Diode

Photon number-resolving detectors are in high demand for applications in photonic quantum technology. In this study, we demonstrate the enhanced capabilities of our self-developed high-efficient InGaAs/InAlAs single-photon avalanche diode for photon number-resolving applications. These capabilities are achieved by harnessing the high multiplication gain generated through an avalanche process in the InAlAs multiplication layer. Significantly, this marks the first instance of intrinsic photon-number resolving using an InGaAs/InAlAs single-photon avalanche diode without multiplexed schemes. We have unambiguously distinguished photon number states up to 5 and achieved the figure of merit of 0.99 by increasing single photon detection efficiency to the maximum value of 46 % while avoiding avalanche saturation that might limit photon number-resolving capabilities.