Supersensitive Polarization Microscopy Using NOON States of Light

Abstract

A quantum polarized light microscope using entangled NOON states with N=2 and N=3 is shown to provide phase supersensitivity beyond the standard quantum limit. We constructed such a microscope and imaged birefringent objects at a very low light level of 50 photons per pixel, where shot noise seriously hampers classical imaging. The NOON light source is formed by combining a coherent state with parametric down-converted light. We were able to show improved phase images with sensitivity close to the Heisenberg limit.

Linear Optical Quantum Metrology with Single Photons: Exploiting Spontaneously Generated Entanglement to Beat the Shot-Noise Limit

“…We answer that question here in the affirmative by showing that a simple, passive, linear-optical interferometer -fed with only uncorrelated, single-photon inputs, coupled with simple, single-mode, disjoint photodetection -is capable of significantly beating the shotnoise limit. Our result implies a pathway forward to practical quantum metrology with readily available technology.Ever since the early work of Yurke & Yuen it has been understood that quantum number-path entanglement is a resource for super-sensitive quantum metrology, allowing for sensors that beat the shotnoise limit [1,2] [7], protein concentration measurements [8], and microscopy [9,10]. This line of work culminated in the analysis of the bosonic NOON state ((|N, 0 + |0, N )/ √ 2, where N is the total number of photons), which was shown to be optimal for local phase estimation with a fixed, finite number of photons, and in fact allows one to hit the Heisenberg limit and the Quantum Cramér-Rao Bound [11][12][13][14].…”

NOON states via a quantum walk of bound particles

“…NOON and dual Fock states [17]) enhance the estimation precision of the phase difference between the output arms of an interferometer [18][19][20][21], making them highly attractive for technological applications. Super-resolution for NOON states with N = 2, 3 has been recently shown experimentally for microscopy purposes [22]. However, the generation of non-classical states with high-fidelity is still a hard task.…”

Integrated generation of complex optical quantum states and their coherent control

“…Entangled optical quantum states represent a key resource for fundamental quantum science and applications such as quantum communications 1 , powerful processing and simulations 2 , as well as metrology and sensing 3 . Indeed, exploiting the full potential of photons for quantum technologies demands access to the custom preparation and coherent While the low-footprint and stability of integrated photonics has made it a highly-competitive platform for the generation and processing of optical quantum states, complex states remain largely inaccessible.…”