Multi-gigahertz operation of photon counting InGaAs avalanche photodiodes

TL;DR

This paper demonstrates a 2 GHz photon counting capability of InGaAs avalanche photodiodes, enabling high-speed single photon detection at telecom wavelengths with reduced afterpulsing, which benefits quantum communication systems.

Contribution

It introduces a self-differencing circuit with tunable frequency and arm balancing, achieving high-speed operation and low afterpulse probability in InGaAs APDs.

Findings

Achieved 2 GHz photon counting with InGaAs APDs.

Reduced afterpulse probability to below 5%.

Enhanced potential for secure quantum key distribution.

Abstract

We report a 2 GHz operation of InGaAs avalanche photodiodes for efficient single photon detection at telecom wavelengths. Employing a self-differencing circuit that incorporates tuneability in both frequency and arm balancing, extremely weak avalanches can now be sensed so as to suppress afterpulsing. The afterpulse probability is characterized as 4.84% and 1.42% for a photon detection efficiency of 23.5% and 11.8%, respectively. The device will further increase the secure bit rate for fiber wavelength quantum key distribution.