Related Experiment Video
Updated: Dec 3, 2025

Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping
Published on: November 7, 2016
Oxygen Gas Sensing with Photothermal Spectroscopy in a Hollow-Core Negative Curvature Fiber
Yingzhen Hong1,2, Haihong Bao1,2, Wei Jin1,2
1Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong, China.
Abstract:
We demonstrate a compact all-fiber oxygen sensor using photothermal interferometry with a short length (4.3 cm) of hollow-core negative curvature fibers. The hollow-core fiber has double transmission windows covering both visible and near-infrared wavelength regions. Absorption of a pump laser beam at 760 nm produces photothermal phase modulation and a probe Fabry-Perot interferometer operating at 1550 nm is used to detect the phase modulation. With wavelength modulation and first harmonic detection, a limit of detection down to 54 parts per million (ppm) with a 600-s averaging time is achieved, corresponding to a normalized equivalent absorption of 7.7 × 10-8 cm-1. The oxygen sensor has great potential for in situ detection applications.
Related Concept Videos
Photoelectric Effect
Photoluminescence: Applications
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to...
Flame Photometry: Overview

