Generation of 10-dB squeezed light from a broadband waveguide optical parametric amplifier with improved phase locking method
Abstract
We report generation of 10.1\pm0.2-dB squeezed light from a broadband periodically poled lithium niobate (PPLN) waveguide optical parametric amplifier (OPA). Based on our previous report where a similar PPLN waveguide shows 8.3-dB squeezing [T. Kashiwazaki et al., Appl. Phys. Lett. 122, 234003 (2023)], we reduce phase fluctuations and overall optical losses in the measurement system. In particular, we introduce a novel phase detection technique that does not require tapping a part of the squeezed light to get a phase locking signal. We use a phase-detection OPA seeded by a tapped probe and pump light before a squeezer OPA. This configuration breaks the conventional trade-off between generating a phase-locking signal with high-signal-to-noise ratio and suppressing degradation of squeezing level caused by optical tapping. With all these improvements, the phase fluctuation angle is reduced from 14 mrad to 9 mrad, and the total optical loss from 12\% to 8\%. Achieving more than 10 dB of squeezing by the broadband waveguide OPA is a significant step towards realization of fault-tolerant ultra-fast universal optical quantum computation.
Cite
@article{arxiv.2511.15082,
title = {Generation of 10-dB squeezed light from a broadband waveguide optical parametric amplifier with improved phase locking method},
author = {Kazuki Hirota and Takahiro Kashiwazaki and Gyeongmin Ha and Taichi Yamashima and Pawaphat Jaturaphagorn and Takumi Suzuki and Kazuma Takahashi and Akito Kawasaki and Asuka Inoue and Warit Asavanant and Mamoru Endo and Takeshi Umeki and Akira Furusawa},
journal= {arXiv preprint arXiv:2511.15082},
year = {2025}
}