A Photon Counting Laser Interferometric Ranging Method

Abstract

The invention discloses a photon counting laser interference distance measurement method. The method combines a laser interferometer with a laser triangulation distance measurement method, adopts a laser triangulation distance measurement method to measure the low-precision distance of an object to be ranged and uses the object to be ranged. The low-precision distance eliminates the multi-wavelength distance uncertainty problem in laser interferometers, and finally realizes high-precision non-cooperative target distance measurement. The advantage of the present invention is that through the application of the single photon detector in the interference, the extremely weak echo light can be detected, thereby realizing the interferometric ranging of the non-cooperative target; at the same time, in combination with the triangular ranging module in the present invention, only Using lasers with a few wavelengths solves the problem of uncertain periods of large-range interference and increases 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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