Multichannel optical path difference detection device and method based on double-loop detection

The invention provides a multichannel optical path difference detection device and method based on double-loop detection. The device comprises a pulse laser and a continuous laser which are connectedwith a synthesis branching unit. The synthesis demultiplexer is connected with the multi-channel optical path regulator, the multi-channel gating device, the to-be-tested device, the collimation emitter, the focusing mirror and the laser demultiplexer in sequence. The laser splitter is connected with the laser imager and the image processor to perform continuous loop optical path difference detection based on continuous interference images, and is connected with the laser detector and the pulse signal processor to perform picosecond pulse-based pulse loop optical path difference detection. Thecontroller controls the device and calculates the detection value of the optical path difference between the two to-be-detected channels in the to-be-detected equipment based on the continuous loop optical path data and the pulse loop optical path difference. According to the invention, the formed double loops refer to each other, the measurement result is optimized, the high-precision digital detection of the optical path difference between the unit laser channels in the multi-channel laser equipment is realized, and the detection precision can reach the sub-millimeter magnitude.