Article

The all-fiber offset-core Fabry-Pérot (OSFP) sensor developed for gas detection has demonstrated sub-ppm sensitivity for acetylene. This sensor, built entirely with fiber, features a 150 μm long sensing cavity and employs photothermal spectroscopy for gas detection.

It operates with a pump laser at 1530.37 nm, achieving a minimum detection limit of 0.39 ppm and a dynamic range of six orders of magnitude. The device is characterized by its compactness and simplicity, avoiding complex alignment and feedback control. Its EMI immunity makes it particularly suitable for harsh environments, with a response time of about 2.1 seconds.