Self consistent, absolute calibration technique for photon number resolving detectors

TL;DR

This paper introduces an absolute calibration method for photon number resolving detectors using a heralded photon source, enabling accurate efficiency measurements without external standards.

Contribution

It presents a novel, self-consistent calibration technique that is independent of reference standards and applicable to advanced photon detectors like Transition Edge Sensors.

Findings

Successfully calibrated a Transition Edge Sensor detector.

Provided quantum efficiency as a function of photon number.

Validated the method's accuracy and independence from heralding detector performance.

Abstract

Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.