Efficient photon number detection with silicon avalanche photodiodes

TL;DR

This paper presents a silicon avalanche photodiode capable of efficiently resolving up to four photons per pulse at visible wavelengths, with high detection efficiency and low dark counts, suitable for quantum information applications.

Contribution

The authors demonstrate a fast, high-efficiency photon number detector using silicon avalanche photodiodes operating near room temperature.

Findings

Detection efficiency of 73.8% at 600 nm

Able to resolve up to four photons per pulse

Dark count probability below 1.1x10^{-6} per gate

Abstract

We demonstrate an efficient photon number detector for visible wavelengths using a silicon avalanche photodiode. Under subnanosecond gating, the device is able to resolve up to four photons in an incident optical pulse. The detection efficiency at 600 nm is measured to be 73.8%, corresponding to an avalanche probability of 91.1% of the absorbed photons, with a dark count probability below 1.1x10^{-6} per gate. With this performance and operation close to room temperature, fast-gated silicon avalanche photodiodes are ideal for optical quantum information processing that requires single-shot photon number detection.