Ultra-narrowband interference circuits enable low-noise and high-rate photon counting for InGaAs/InP avalanche photodiodes

TL;DR

This paper introduces an ultra-narrowband interference circuit (UNIC) that significantly reduces capacitive response and enables high-rate, low-noise photon counting in InGaAs/InP APDs, improving performance for quantum applications.

Contribution

The paper presents a novel UNIC design that effectively suppresses capacitive response, allowing high count rates and low afterpulsing in InGaAs/InP APDs, which was not achieved with previous circuits.

Findings

Achieved up to 700 million counts per second.

Reduced afterpulsing to 0.5% at 25.3% efficiency.

Demonstrated effective capacitive response rejection up to 80 dB per stage.

Abstract

Afterpulsing noise in InGaAs/InP single photon avalanche photodiodes (APDs) is caused by carrier trapping and can be suppressed successfully through limiting the avalanche charge via sub-nanosecond gating. Detection of faint avalanches requires an electronic circuit that is able to effectively remove the gate-induced capacitive response while keeping photon signals intact. Here we demonstrate a novel ultra-narrowband interference circuit (UNIC) that can reject the capacitive response by up to 80 dB per stage with little distortion to avalanche signals. Cascading two UNIC's in a readout circuit, we were able to enable high count rate of up to 700 MC/s and low afterpulsing of 0.5 % at a detection efficiency of 25.3 % for 1.25 GHz sinusoidally gated InGaAs/InP APDs. At -30 degree C, we measured 1 % afterpulsing at a detection efficiency of 21.2 %.