Part-per-billion level photothermal nitric oxide detection at 5.26 μm using antiresonant hollow-core fiber-based heterodyne interferometry

In this work, I demonstrate a novel configuration of a photothermal gas sensor. Detection of nitric oxide at a wavelength of 5.26 mu m was possible by constructing an absorption cell based on a self-fabricated antiresonant hollow core fiber characterized by low losses at both the pump and probe wavelengths. Proper design of the sensor allowed using the heterodyne interferometry-based signal readout of the refractive index modulation, which yielded a record noise equivalent absorption of 2.81x10(-8) cm(-1) for 100 s integration time for mid-infrared fiber-based gas sensors. The obtained results clearly demonstrate the full potential of using properly designed antiresonant hollow core fibers in combination with sensitive gas detection methods. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

By utilizing a self-fabricated antiresonant hollow core fiber and sensitive gas detection methods, this study demonstrates a novel configuration of a photothermal gas sensor, enabling efficient detection of nitric oxide.