Quantum-like nonlinear interferometry with frequency-engineered classical light

TL;DR

This paper introduces a classical nonlinear optical method that mimics quantum interferometry, achieving super-resolution and higher signal-to-noise ratio with high-brightness lasers, enabling faster and broader bandwidth signal detection.

Contribution

It presents a quantum-like nonlinear interferometry technique using classical light, surpassing quantum methods in signal-to-noise ratio and acquisition speed.

Findings

Achieves super-resolution in single-photon detection regime.

Replaces photon-pairs with coherent states to mimic quantum properties.

Provides a pathway for faster, broader bandwidth quantum sensing.

Abstract

Quantum interferometry methods exploit quantum resources, such as photonic entanglement, to enhance phase estimation beyond classical limits. Nonlinear optics has served as a workhorse for the generation of entangled photon pairs, ensuring both energy and phase conservation, but at the cost of limited rate and degraded signal-to-noise ratio compared to laser-based interferometry approaches. We present a "quantum-like" nonlinear optical method that reaches super-resolution in single-photon detection regime. This is achieved by replacing photon-pairs by coherent states of light, mimicking quantum properties through classical nonlinear optics processes. Our scheme utilizes two high-brightness lasers. This results in a substantially greater signal-to-noise ratio compared to its quantum counterpart. Such an approach paves the way to significantly reduced acquisition times, providing a pathway to explore signals across a broader range of bandwidth. The need to increase the frequency bandwidth of the quantum sensor significantly motivates the potential applications of this pathway.