Photostatistics Reconstruction via Loop Detector Signatures

TL;DR

This paper introduces a signature-based method for photon-number reconstruction using loop detectors, improving robustness and accuracy over traditional count-based approaches in quantum optical measurements.

Contribution

The paper presents a novel signature-based reconstruction technique for photon-number resolving detectors that enhances robustness and reduces assumptions compared to existing methods.

Findings

Signature approach is more robust against calibration errors.

Reduced statistical uncertainty in photon-number reconstruction.

Less reliance on a-priori assumptions about the input quantum state.

Abstract

Photon-number resolving detectors are a fundamental building-block of optical quantum information processing protocols. A loop detector, combined with appropriate statistical processing, can be used to convert a binary on/off photon counter into a photon-number-resolving detector. Here we describe the idea of a signature of photon-counts, which may be used to more robustly reconstruct the photon number distribution of a quantum state. The methodology is applied experimentally in a 9-port loop detector operating at a telecommunications wavelength and compared directly to the approach whereby only the number of photon-counts is used to reconstruct the input distribution. The signature approach is shown to be more robust against calibration errors, exhibit reduced statistical uncertainty, and reduced reliance on a-priori assumptions about the input state.