Remote Preparation of Bright Squeezed Light via Field-Deployed Multi-Core Fibers

We developed a novel scheme for remote preparation of bright squeezed light using standard fiber-based components over field-deployed multi-core fibers. By implementing two phase-locked loops, we successfully generated bright amplitude-squeezed light over a 6 km laboratory single-mode fiber and a 17 km field-deployed multi-core fiber with measured squeezing levels of −2.52 dB and −1.80 dB, respectively. We also observed bright phase-squeezed light in the two scenarios with squeezing levels of −2.01 dB and −0.91 dB. We also measured results similar to those of the deployed fiber by using a 30 km laboratory single-mode fiber with comparable optical loss. The squeezed properties were confirmed with reconstructed Wigner functions using quantum state tomography. Our approach enabled remote users to access user-defined squeezed light based on a single seed laser, thereby maintaining coherence between their squeezed states, which could find applications in fiber-based quantum information processing and quantum metrology.