Gas detecting system based on EFPI sensor of hollow PCF

The utility model discloses a gas detecting system based on an EFPI (Extrinsic Fabry-Perot Interferometric) sensor of a hollow PCF (Photonic Crystal Fiber). The gas detecting system comprises a laser, wherein an optical emission device is arranged on an optical path before the laser; a measuring gas chamber is arranged on an optical path before the optical emission device; an optical detector is arranged at the light emergence end of the measuring gas chamber; the electrical signal output terminal of the optical detector is connected with a data acquisition and processing module; the signal output terminal of the data acquisition and processing module is connected with a computer; the measuring gas chamber adopts the EFPI sensor of the hollow PCF. Specific-wavelength light emitted by the laser is emitted to the measuring gas chamber through the optical emission device; the optical detector receives gas with concentration information from the measuring gas chamber, performs photoelectric conversion, transmits