Gas concentration sensor and gas concentration detection device

The invention is applicable to the technical field of gas measurement sensing devices, and provides a gas concentration sensor and a gas concentration detection device. The gas concentration sensor comprises a first optical fiber, a hollow-core photonic crystal fiber and a second optical fiber which are sequentially arranged, and the hollow-core photonic crystal fiber is of a hollow tubular structure; an acoustic resonant cavity is formed in the tubular structure of the hollow-core photonic crystal fiber, and probe light and pump light are incident from the end, away from the hollow-core photonic crystal fiber, of the first fiber. The miniaturization of the probe of the photoacoustic spectroscopy sensor is realized, and the sensor can be suitable for measurement under the conditions of trace gas, micro space and the like; long-distance measurement can be carried out only by extending the optical fiber; the whole acoustic resonant cavity is filled with photoacoustic sound wave information, the photoacoustic in