InGaAs/InP single-photon detectors with 60% detection efficiency at 1550 nm

TL;DR

This paper reports a high-efficiency InGaAs/InP single-photon detector achieving 60% PDE at 1550 nm through structural optimization and advanced readout circuitry, significantly enhancing near-infrared photon detection performance.

Contribution

The authors developed a high-frequency gated InGaAs/InP SPD with 60% PDE by optimizing device structure and readout circuit design, advancing the state-of-the-art in photon detection efficiency.

Findings

Achieved 60% PDE at 1550 nm with 1.25 GHz gating.

Reduced afterpulsing with optimized circuit and operation conditions.

Enhanced photon absorption efficiency by approximately 20%.

Abstract

InGaAs/InP single-photon detectors (SPDs) are widely used for near-infrared photon counting in practical applications. Photon detection efficiency (PDE) is one of the most important parameters for SPD characterization, and therefore increasing PDE consistently plays a central role in both industrial development and academic research. Here we present the implementation of high-frequency gating InGaAs/InP SPD with a PDE as high as 60% at 1550 nm. On one hand, we optimize the structure design and device fabrication of InGaAs/InP single-photon avalanche diode with an additional dielectric-metal reflection layer to relatively increase the absorption efficiency of incident photons by ~ 20%. On the other hand, we develop a monolithic readout circuit of weak avalanche extraction to minimize the parasitic capacitance for the suppression of the afterpulsing effect. With 1.25 GHz sine wave gating and optimized gate amplitude and operation temperature, the SPD is characterized to reach a PDE of 60% with a dark count rate (DCR) of 340 kcps. For practical use, given 3 kcps DCR as a reference the PDE reaches ~ 40% PDE with an afterpulse probability of 5.5%, which can significantly improve the performance for the near-infrared SPD based applications.