Photon-counting laser interference range-finding method

Abstract

The invention discloses a photon-counting laser interference range-finding method, and the method combines a laser interferometer and laser triangular range finding, achieves the measurement of the low-precision distance of a to-be-measured object in the mode of laser triangular range finding, solves a problem that the multi-wavelength distance in the laser interferometer is uncertain through thelow-precision distance of the to-be-measured object, and finally achieves the high-precision non-cooperative target distance measurement. The method advantageous in that a single-photon detector in the interference can achieve the detection of greatly weak echo light, and achieves the interference range finding of a non-cooperative target; meanwhile, the method just employs the laser at a few wavelengths through combining with a triangular range finding module, solves a problem that a large-range interference period is uncertain, and enlarges the measurement range.

Description

technical field [0001] The invention belongs to the technical field of laser distance measurement, and in particular relates to a photon counting laser interference distance measurement method. Background technique [0002] At present, the laser triangulation method is the most mature and widely used method for high-precision laser ranging of non-cooperative targets. The measurement accuracy can reach 1 micron within the measurement range of 10 mm, which is limited by the pixel size of the CCD (or CMOS) sensor. constraints, it is difficult to further improve the measurement accuracy of this method. [0003] The working principle of the Michelson laser interferometer is to split the incident light into two mutually perpendicular beams through the beam splitter, and then converge to the same optical path after being reflected by the two arm mirrors. The two converged beams meet the interference conditions, thus forming interference fringes . The change period of the interfer...

AI Technical Summary

Problems solved by technology

However, in all interferometric ranging methods, due to the need for strong reflected light to form high-contrast interference fringes, which are then detected by photodetectors, usually only cooperative targets are suitable, which limits the application range of interferometric ranging

[0005] In order to realize more applications of interferometric ranging, it is necessary to solve this problem. When performing interferometric ranging on non-cooperative targets, due to the diffuse reflection of the laser on the surface of the object, the echo light is too weak to achieve phase detection.

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