Practical high-precision quadrant-detector (QD) Gaussian spot centroid positioning method

Abstract

The invention discloses a practical high-precision quadrant-detector (QD) Gaussian spot centroid positioning method, and relates to the field of laser spot positioning. The solved technical problem isabout overcoming the shortcomings that existing algorithms directly calculate spot centroid, and the same is related to spot radii. The method comprises the following steps: step 1, using a quadrantdetector to carry out four-way output of photocurrents to calculate solution values of spot centroid; step 2, using the center of the quadrant detector as a coordinate origin to establish a Cartesiancoordinate system, and using a Gaussian spot energy distribution model to construct a finding table of one-to-one corresponding of spot centroid solution values and relative positions according to a precision requirement; step 3, finding a corresponding relative position in the finding table, which is constructed in the step 2, according to the solution values in the step 1; step 4, correcting a result, which is found in the step 3, if precision does not meet the requirement, and carrying out the next step if the precision meets the requirement; and step 5, calculating spot centroid accordingto a spot radius and a relative position in the step 4.

Description

technical field [0001] The invention relates to the technical field of laser spot positioning, in particular to a practical high-precision four-quadrant detector Gaussian spot centroid positioning method. Background technique [0002] Quadrant Detector (QD) is a commonly used position detection sensor. It has been widely used due to its simple signal processing circuit, wide wavelength response range, low inherent noise level, high sensitivity and fast response speed. It is used in fields that need to provide high-precision micro-displacement or angle measurement, such as laser alignment, laser guidance, laser monitoring, laser tracker and space laser communication. [0003] There are two main factors that affect the detection accuracy of the laser spot position: one is the random error caused by the random fluctuation of the calculated value caused by the noise of the signal processing circuit, background light and atmospheric turbulence. The other is the inherent error of...

AI Technical Summary

Problems solved by technology

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the existing algorithm to directly calculate the centroid of the spot, which is related to the radius of the spot, and provide a practical high-precision four-quadrant detector Gaussian spot centroid positioning method, which greatly improves the positioning accuracy and speeds up the processing. speed and increased ease of use

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