Sub-shot-noise transmission measurement scheme using a time multiplexing single-photon source

KNOLL, L.T.; AGUSTINA GABRIELA MAGNONI; MIGUEL ANTONIO LAROTONDA

Workshop; Bristol Quantum Information Technologies Workshop 2020; 2020

A very promising result from optical quantum metrology is the ability to achieve sub shotnoise variance in transmission/absorption measurements. This is due to the significantlylower uncertainty in light intensity of quantum beams with respect to their classicalcounterparts. In this work, we simulate results from an experiment that uses a multiplexedsingle photon source [1] in this kind of measurements, considering all the experimentallosses.The single photon source is based on pair generation by spontaneous parametric downconversion (with CW pumping) and a subsequent time multiplexing set-up based on a binarydivision strategy. This enables the synchronization of the output photon with an externalclock signal at the same time that increases the single photon probability of the source. Thesubpoissonian statistics of the output signal is the key for achieving sub shot noiseperformance. Two remarkable features of this proposal are, on the one hand, that there is noneed for number resolving detectors, and on the other hand, that it works in a very low lightregime, enabling minimum disruption on the measurement of biological or other fragilesamples.[1] Magnoni, A.G., López Grande, I.H., Knoll, L.T., Larotonda, M.A. Performance of atemporally multiplexed single-photon source with imperfect device. Quantum Inf Process 18,311 (2019). https://doi.org/10.1007/s11128-019-2417-0