All-optical switching and squeezed light generation in periodically poled lithium niobate waveguides

Xianglong Zeng, Xianfeng Chen, Yuping Chen +2 more

Qingtang Zhang

Shigehiko Mori, Jonas Söderholm, Naoto Namekata +1 more

Sarah Dugan

Xiaodong Shi, Angela Anna Baiju, Xu Chen +12 more

Squeezed states of light play a key role in quantum-enhanced sensing and continuous-variable quantum information processing. Realizing integrated squeezed light sources is crucial for developing compact and scalable photonic quantum systems. In this work, we demonstrate on-chip broadband vacuum squeezing at telecommunication wavelengths on the thin-film lithium niobate (TFLN) platform. Our device integrates periodically poled lithium niobate (PPLN) nanophotonic waveguides with low-loss edge couplers, comprising bilayer inverse tapers and an SU-8 polymer waveguide. This configuration achieves a fiber-to-chip coupling loss of 1.4 dB and a total homodyne detection loss of 4.0 dB, enabling a measured squeezing level of 1.4 dB. Additional measurements in a more efficient PPLN waveguide (without low-loss couplers) infer an on-chip squeezing level of approximately 10 dB at a pump power of 62 mW. These results underscore the potential of TFLN platform for efficient and scalable squeezed light generation.

Xiaodong Shi, Angela Anna Baiju, Sakthi Sanjeev Mohanraj +8 more

We demonstrate an on-chip telecom-wavelength squeezer using a periodically poled thin-film lithium niobate waveguide. With a single-pass, continuous-wave pump at 49 mW, we measure -0.64 dB squeezing and 4.30 dB anti-squeezing (11 dB inferred on-chip).