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Phase-Dependent Squeezing in Dual-Comb Interferometry

Daniel I. Herman1,*,†, Molly Kate Kreider1,2, Noah Lordi2, Mathieu Walsh3, Eugene J. Tsao1, Alexander J. Lind1, Matthew Heyrich1,2, Joshua Combes1, Scott A. Diddams1,2,‡ et al.

Jérôme Genest3,§

  • *Present address: Sandia National Laboratories, Albuquerque, New Mexico, USA.
  • †Contact author: diherma@sandia.gov
  • ‡Contact author: scott.diddams@colorado.edu
  • §Contact author: jgenest@gel.ulaval.ca
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Phys. Rev. Lett. 136, 163601 – Published 20 April, 2026

DOI: https://doi.org/10.1103/31w7-69c8

Abstract

Manipulating the quantum noise of continuous-wave lasers through squeezing has reshaped optical interferometry. However, progress in optical frequency comb interferometry with pulsed squeezed sources has been limited, despite the role of frequency combs in ultraprecise optical metrology. Here, we introduce a new time-domain approach to characterizing squeezed femtosecond light pulses using dual-comb interferometry. Time-domain interferograms are generated via multiheterodyne beating between the modes of a Kerr soliton-squeezed frequency comb and a coherent state comb. The interferogram noise reveals phase-dependent squeezing and antisqueezing, dipping as much as 3.8±0.2  dB below the shot noise level at alternating zero crossings. We model this nonstationary quantum noise as a periodic optical displacement of the squeezed comb by the coherent comb. These results support a route toward quantum-enhanced dual-comb timing applications and high-speed quantum state tomography with dual-comb interferometers.

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Phys. Rev. Lett. 136, 163601– Published 20 April, 2026
  • Received 23 June 2025
  • Accepted 3 February 2026
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