近日，美国科罗拉多大学的Scott A. Diddams&Daniel I. Herman与加拿大拉瓦尔大学的Jerome Genest等人合作并取得一项新进展。经过不懈努力，他们揭示压缩双梳光谱学。相关研究成果已于2025年1月16日在国际权威学术期刊《科学》上发表。
光学频率梳在宽带、高分辨率光谱学和精密干涉测量中展现了独特优势。然而，量子力学最终限制了激光频率梳所能达到的计量精度。量子压缩已在连续波激光器中实现了显著的测量改进，但展示压缩频率梳在计量学上的优势的实验尚不够成熟。
利用非线性光纤中的克尔效应，该研究团队对中心波长为1560纳米的1吉赫兹频率梳进行了幅度压缩，在2.5太赫兹带宽内压缩程度超过3分贝。双梳干涉测量技术实现了对硫化氢气体的模分辨光谱学分析，信噪比超出散粒噪声极限近3分贝。量子噪声的降低使气体浓度测定的量子速度提高了两倍，这对动态化学环境中多种物质的高速测量具有重要意义。
附：英文原文
Title: Squeezed dual-comb spectroscopy
Author: Daniel I. Herman, Mathieu Walsh, Molly Kate Kreider, Noah Lordi, Eugene J. Tsao, Alexander J. Lind, Matthew Heyrich, Joshua Combes, Jérome Genest, Scott A. Diddams
Issue&Volume: 2025-01-16
Abstract: Optical frequency combs have enabled unique advantages in broadband, high-resolution spectroscopy and precision interferometry. However, quantum mechanics ultimately limits the metrological precision achievable with laser frequency combs. Quantum squeezing has led to significant measurement improvements with continuous wave lasers, but experiments demonstrating metrological advantage with squeezed combs are less developed. Using the Kerr effect in nonlinear optical fiber, a 1 GHz frequency comb centered at 1560 nm is amplitude-squeezed by >3 dB over a 2.5 THz bandwidth. Dual-comb interferometry yields mode-resolved spectroscopy of hydrogen sulfide gas with a signal-to-noise ratio nearly 3 dB beyond the shot-noise limit. The quantum noise reduction leads to a two-fold quantum speedup in the determination of gas concentration, with impact for high-speed measurements of multiple species in dynamic chemical environments.
DOI: 10.1126/science.ads6292