报告题目：Frequency comb breathalyzer at the record performance limit

报告人：Dr. Qizhong Liang

报告人单位： JILA and University of Colorado Boulder, USA

主持人：李文雪 研究员

地点：光学大楼A508会议室

时间：2025年12月13日（周六）10:00-11:00

报告内容：

Molecules exhaled from human breath vary in concentration with medical conditions, enabling non-invasive, rapid, and low-cost diagnostics. In 2021, we achieved multi-species breath detection sensitivity at >100 parts-per-trillion (ppt). In 2023, we reported the first use of frequency combs for breath diagnostics: a 170-subject COVID-19 trial achieved 85% accuracy via supervised machine learning. Detecting more molecular species promises richer discriminatory information for better diagnostic accuracy. To this end, we invented Modulated Ringdown Comb Interferometry (MRCI), a technique enabling dispersion-free measurement of mid-infrared photon absorption dynamics across over 100,000 discrete optical frequencies. With MRCI, we have 1) set new sensitivity and spectral coverage records (>1 ppt; >1,000 cm-1), with demonstrations to simultaneously quantify 20 species from breath and ambient air varying in concentrations by 7 orders of magnitude; and 2) achieved robust, high-efficiency performance for universal sensing of complex real-world gas samples, enabling us to conduct multiple new breath studies in parallel. With the advent of large-scale frequency comb datasets for health, I will discuss new opportunities on using MRCI's massive data to enable a data-driven methodology for more interpretable predictive modeling.

报告人简介：

Dr. Qizhong Liang received his Physics PhD degree in 2025 from Prof. Jun Ye’s group at JILA and the University of Colorado Boulder, where he continues as a postdoctoral researcher. His research on frequency comb breath diagnostics integrates ultrafast optics, precision metrology, machine learning, statistics, and medical science. His work has been featured in Scientific American, Physicsworld, and Photonics West Show Daily, and he has delivered over 10 invited talks at conferences including CLEO and Photonics West, and universities including Stanford, Chicago, and Maryland.