Nested Ring Resonant Sagnac-Enhanced Photothermal Gas Sensing Using a Nanofiber
Abstract
Photothermal (PT) spectroscopy exhibits exceptional selectivity and high sensitivity for trace gas detection, yet developing PT gas sensors that combine fast response, high sensitivity, and practical usability remains a significant challenge. Here, we demonstrate a nested ring resonant Sagnac-enhanced PT gas sensor using a nanofiber. By inserting a nested ring resonator within the Sagnac loop, the proposed sensor reduces the full width at half-maximum of the resonance peak, thereby enhancing the cavity finesse and improving the sensitivity of PT phase modulation. With a 2 cm-long nanofiber and a resonator finesse of 73, the sensor achieves precise C 2 H 2 detection featuring a noise equivalent concentration of 16 ppb, a 19 s response time, and
Fields of Study & Subjects
Advanced Fiber Optic Sensors
Mechanical and Optical Resonators
Spectroscopy and Laser Applications
Publication details
- Journal / source
- Analytical Chemistry
- Publisher
- American Chemical Society (ACS)
- Volume
- 98
- Issue
- 10
- Pages
- 7224–7232
- Publication date
- 5 March 2026
- Language
- EN