Experimental super-resolved phase measurements with shot-noise sensitivity

TL;DR

This paper demonstrates super-resolved optical phase measurements surpassing classical limits using quantum and classical detection schemes, achieving up to 288 times better resolution than the wavelength.

Contribution

It introduces experimental methods for phase measurement with shot-noise sensitivity surpassing classical limits, using photon-number resolving and standard detectors.

Findings

Deterministic single-shot super-resolution up to 288 times better than wavelength.

Measurements follow classical sensitivity limits, up to 86 times better.

Comparison of quantum and classical detection schemes shows advantages of photon-number resolving detectors.

Abstract

The ultimate sensitivity of optical measurements is a key element of many recent works. Classically, it is mainly limited by the shot noise limit. However, a measurement setup that incorporates quantum mechanical principles can surpass the shot noise limit and reach the Heisenberg limit. Nevertheless, many of those experiments fail to break even the classical shot-noise limit. Following a recent proposal, we present here the results of optical phase measurements with a photon-number resolving detector using coherent states of up to 4200 photons on average. An additional scheme that can be implemented using standard single-photon detectors is also presented, and the results of the two schemes are compared. These measurements present deterministic single-shot sub-wavelength super-resolution up to 288 better than the optical wavelength. The results follow the classically limited sensitivity, up to 86 times better than the wavelength.