Wan Zhuoren, Chen Yuan, Zhang Xiuxiu, Yan Ming, Zeng Heping
State Key Laboratory of Precision Spectroscopy, and Hainan Institute, East China Normal University, Shanghai, China.
Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, 401120, Chongqing, China.
Light Sci Appl. 2025 Aug 1;14(1):257. doi: 10.1038/s41377-025-01891-1.
Dual-comb spectroscopy (DCS) is a powerful technique for spectroscopic sensing, offering exceptional spectral bandwidth, resolution, precision, and speed. However, its performance is fundamentally limited by quantum noise inherent to coherent-state optical combs. Here, we overcome this barrier by introducing quantum correlation-enhanced DCS using correlated twin combs generated via seeded four-wave mixing. One comb acts as a local oscillator to decode molecular signals, while the twin suppresses shot noise through intensity-difference squeezing, achieving a 2 dB signal-to-noise ratio improvement beyond the shot-noise limit-equivalent to a 2.6× measurement speed enhancement. Notably, when coupled with up-conversion spectroscopy, our technique records comb-line-resolved, high-resolution (7.5 pm) spectra in the critical 3 μm region for molecular fingerprinting. These results bridge quantum optics and frequency comb spectroscopy, offering great potential for trace gas detection, precision metrology, and chemical analysis. Future developments in detector efficiency and nanophotonic integration could further enhance its scalability and impact.
双梳光谱技术（DCS）是一种用于光谱传感的强大技术，具有出色的光谱带宽、分辨率、精度和速度。然而，其性能从根本上受到相干态光梳固有量子噪声的限制。在此，我们通过引入量子关联增强的DCS克服了这一障碍，该技术使用通过种子四波混频产生的关联孪生光梳。一个光梳充当本地振荡器来解码分子信号，而孪生光梳通过强度差压缩抑制散粒噪声，实现了比散粒噪声极限提高2dB的信噪比——相当于测量速度提高2.6倍。值得注意的是，当与上转换光谱技术相结合时，我们的技术在用于分子指纹识别的关键3μm区域记录了梳状线分辨的高分辨率（7.5pm）光谱。这些结果架起了量子光学与频率梳光谱学之间的桥梁，在痕量气体检测、精密计量和化学分析方面具有巨大潜力。探测器效率和纳米光子集成方面的未来发展可能会进一步提高其可扩展性和影响力。
