2026-03-05 NTT株式会社,東京大学,理化学研究所,OptQC株式会社
図1 (a)スクイーズド光の量子ノイズ (b)導波路型デバイスによるスクイージングレベルの変遷
（広帯域性を発揮する導波路型光デバイスでの高スクイージングレベルが近年求められている）
＜関連情報＞
- https://group.ntt/jp/newsrelease/2026/03/05/260305a.html
- https://opg.optica.org/oe/fulltext.cfm?uri=oe-34-5-7958
改良位相同期法を用いた広帯域導波路光パラメトリック増幅器からの10dBスクイーズド光の生成 Generation of 10-dB squeezed light from a broadband waveguide optical parametric amplifier with improved phase locking method
Kazuki Hirota, Takahiro Kashiwazaki, Gyeongmin Ha, Taichi Yamashima, Pawaphat Jaturaphagorn, Takumi Suzuki, Kazuma Takahashi, Akito Kawasaki, Asuka Inoue, Warit Asavanant, Mamoru Endo, Takeshi Umeki, and Akira Furusawa
Optics Express Published: February 25, 2026
DOI:https://doi.org/10.1364/OE.585323
Abstract
We report detection of 10.1 ± 0.2-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)
Crossref ], we reduce phase fluctuations and overall optical losses in the measurement system. In particular, we introduce a 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 a high signal-to-noise ratio and suppressing the degradation of the 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 the realization of fault-tolerant ultra-fast universal optical quantum computation.
