Divide-and-Conquer: An integrated photon-counting scheme

TL;DR

This paper introduces a scalable divide-and-conquer method for photon counting that transforms incident light into uniform distributions, enabling accurate photon-number resolution with standard detectors, advancing integrated quantum photonics.

Contribution

The authors develop a novel divide-and-conquer approach that overcomes conversion uncertainties, allowing scalable photon-number-resolving detection using standard on-off detectors.

Findings

Successfully demonstrated transformation into uniform distributions

Achieved accurate photon-number resolution at high photon fluxes

Paved the way for integrated photon-number-resolving detectors

Abstract

The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to overcome these limitations by transforming the incident fields into uniform distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream are obtained from the click statistics, our technique is freely scalable to accommodate - in principle - arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detectors for advanced on-chip photonic quantum networks.