UChicago PME Quantum Science and Engineering Seminar- Qizhong Liang

Exhaled breath diagnosis with record-breaking frequency comb gas sensors

Molecules exhaled from breath undergo concentration changes in the presence of medical conditions, facilitating non-invasive and real-time diagnostics. Using cavity-enhanced frequency comb spectroscopy—a broadband laser absorption spectroscopy technique—we demonstrated COVID-19 breath detection with 85 % accuracy in a 170-subject cohort. Since then, we have upgraded our detection capabilities to achieve single-digit part-per-trillion sensitivity and over a thousand wavenumber coverage in the mid-infrared. This new record-sensing performance is enabled by a new interferometry method, allowing high-throughput and robust measurement of photon absorption rates at massively parallel discrete optical frequencies. Gas samples of arbitrarily complex and unknown composition can now be measured non-destructively within seconds. Our latest work focuses on the development of a data-driven method for molecular species identification directly from the frequency comb absorption spectroscopy datasets. Host: Peter Maurer. This event welcomes participants from all backgrounds and attendance is open to all.