Method for obtaining high-precision positioning of Gaussian beam based on four-quadrant detector

Abstract

The invention discloses a method for obtaining high-precision positioning of a Gaussian beam based on a four-quadrant detector. The method comprises the following steps: to begin with, establishing apixel matrix module, the initial value of which is 0, according to image plane size of the four-quadrant detector; then, according to a Gaussian distribution function, establishing a light spot, the energy of which obeys the Gaussian distribution, to simulate imaging information of the Gaussian beam on the image plane of the four-quadrant detector after passing through an optical system; obtainingvalues of the Gaussian light spot in four quadrants at different positions within a certain range on the pixel matrix module respectively; calculating a theoretical light spot center coordinate basedon the four values by utilizing a conventional positioning algorithm; and finally, carrying out comparison analysis on the theoretical center coordinate and actual center coordinate, and obtaining ahigh-precision positioning algorithm through a polynomial fitting method. The obtained Gaussian beam positioning algorithm has the advantages of high precision, fast processing speed and high resolution and the like.

Description

technical field [0001] The invention relates to the field of laser positioning, in particular to a method for obtaining Gaussian beam high-precision positioning based on a four-quadrant detector. Background technique [0002] The four-quadrant detector is based on the photovoltaic effect. Photolithography is often used to divide the photosensitive surface of the PIN photodiode or APD avalanche diode into four regions with the same shape and area. The positions of the regions are symmetrical to each other, and each region occupies A quadrant, there is an interval between every two quadrants, this interval is commonly known as the dead zone (Dark Zone), the requirement for the width of the dead zone is relatively strict, if the "dead zone" is too wide, when the incident spot is small, it is impossible to distinguish the spot position; if the "dead zone" is too narrow, it may cause crosstalk between signals, and the requirements for the process are also high. [0003] The lase...

AI Technical Summary

Problems solved by technology

The actual spot energy is not evenly distributed, and most of the laser spot energy is Gaussian distributed. The center positioning algorithm corresponding to the Gaussian distributed spot is very complicated and requires a large amount of calculation. Most of the algorithms are left in theoretical research and numerical simulation. stage, and can not meet the requirements of high precision

In addition, due to the structure of the four-quadrant detector, there will be a certain width of the dead zone, and most algorithms do not take the dead zone into account, so compared with the center coordinates of the actual spot on the detector, these algorithms The accuracy of the obtained center coordinates is not very high

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