Phase shifter online calibration method and device

Abstract

The invention relates to an online calibration method and device for a phase shifter. The method comprises the following steps: a, building an optical path environment for calibration; b, adjusting the measuring plate to enable the detector to generate longitudinal stripes; c, marking each calibration scale line on the measuring plate; d, recording the initial voltage of the phase shifter, and slowly changing the voltage of the phase shifter in one direction to enable the stripes to move slowly; e, recording the voltage of the phase shifter when the fringes pass through each calibration scale line; f, the phase shifter is adjusted back to the initial voltage, and the steps d and e are repeated; and g, calculating and issuing a phase shifter calibration value. According to the method, the problems that an off-line phase shifter calibration method is inconvenient to use and calibration algorithm errors are not easy to judge can be solved.

Description

technical field [0001] The invention relates to an online calibration method and device for a phase shifter. Background technique [0002] The phase shifter is a key component of the laser shearing speckle interferometer, which generally uses piezoelectric ceramics as the driving component. Due to the limited manufacturing process and performance stability of piezoelectric ceramics, coupled with the influence of the detection environment, its expansion properties will also fluctuate, so it needs to be calibrated periodically. The calibration effect of the phase shifter will also directly affect the image quality detected by the laser speckle interferometer, and then affect the final measurement accuracy. In the prior art, offline calibration methods based on fringe analysis and mathematical statistical methods are generally used. This method requires statistical algorithms based on mathematical models to complete, so complex iterative operations are required, and it is easi...

AI Technical Summary

Problems solved by technology

Due to the limited manufacturing process and performance stability of piezoelectric ceramics, coupled with the influence of the detection environment, its expansion properties will also fluctuate, so it needs to be calibrated periodically

The calibration effect of the phase shifter will also directly affect the image quality detected by the laser speckle interferometer, and then affect the final measurement accuracy

In the prior art, an offline calibration method based on fringe analysis and mathematical statistical methods is generally used. This method requires a statistical algorithm based on a mathematical model to complete, so complex iterative operations are required, and it is easy to be affected by the accuracy of the model and cause calibration errors.

In addition, offline measurement requires disassembly and assembly of the phase shifter, so it will not only cause inconvenience in use, but also be affected by new errors generated when the phase shifter is disassembled.

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