Spatial domain multiplexing demodulation instrument of optical fiber photoacoustic sensor

The utility model discloses a spatial domain multiplexing demodulation instrument of an optical fiber photoacoustic sensor. The demodulation instrument comprises a broadband light source, an optical fiber splitter, a plurality of groups of optical fiber photoacoustic sensing channels, a glass sheet, a photodiode array, a data acquisition and processing circuit and a communication module, wide-spectrum light emitted by the wide-spectrum light source is divided into a plurality of beams by the optical fiber splitter and enters the multiple sets of optical fiber opto-acoustic sensing channels at the same time, and reflected signal light enters the glass sheet at the same time after passing through the corresponding optical fiber opto-acoustic sensing channels. Gaussian divergent light reflected from the surface of the glass sheet is projected to different space areas of the photodiode array and then is received by the photodiode array; the data acquisition and processing circuit is connected with the photodiode