Phase-Dependent Squeezing in Dual-Comb Interferometry

TL;DR

This paper demonstrates phase-dependent Kerr soliton squeezing in dual-comb interferometry, revealing non-stationary quantum noise variations that can be below shot noise, with implications for quantum-enhanced timing and high-speed quantum tomography.

Contribution

It presents the first measurement of phase-dependent Kerr squeezing in dual-comb interferograms, linking quantum noise behavior to comb displacement and phase, supported by a quantum noise model.

Findings

Quantum noise dips below shot noise by 3.8 dB.

Squeezing varies with interferogram phase, showing non-stationary behavior.

Supports potential for quantum-enhanced dual-comb applications.

Abstract

We measure phase-dependent Kerr soliton squeezing and anti-squeezing in the time-domain dualcomb interferograms generated using two independent frequency comb lasers. The signal appears as non-stationary quantum noise that varies with the fringe phase of the interferogram and dips below the shot-noise level by as much as 3.8 dB for alternating zero-crossings. The behavior arises from the periodic displacement of the Kerr squeezed comb by the coherent field of the second frequency comb, and is confirmed by a quantum noise model. These experiments support a route towards quantum-enhanced dual-comb timing applications and raise the prospect of high-speed quantum state tomography with dual-comb interferometry.