Multi-point optical fibre oxygen sensor based on laser absorption spectroscopy

Based on laser absorption spectroscopy and optical fibre sensing technology, this study proposed an optical fibre oxygen detection sensor. Moreover, using a vertical cavity surface emitting laser (VCSEL) with a wave length of 763 nm as the light source, a Herriot principle-based optical fibre long-optical path detection air chamber was developed, which resulted in the stable, long-term operation of the system. This oxygen detection system covered the full possible measuring range of 0–100% with a detection error of less than 0.15%. Moreover, it realised multi-channel detection at maximum of 3 km. The results showed that the oxygen sensor showed good performance and stability and was applicable to on-line detection in an environment containing multiple- and long-distance targets.