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Study of laser beam pointing stability measuring system based on F-theta lens

Since laser beam pointing stability affects the quality and accuracy of work in areas such as laser guidance and laser processing, the paper proposes a method for measuring the laser beam pointing stability based on the linearly angle-displacement transformation characteristics of F-theta lens in order to measure the pointing stability accurately and comprehensively and evaluate the performance of the laser. The method linearly converts an angular offset into a displacement offset that can be accurately measured and evaluate the pointing stability by means of finding the minimum envelope circle. Based on this method, a laser beam pointing stability measurement system with CCD camera as image acquisition unit is built for He-Ne laser source. The experimental results show that the pointing stability of the He-Ne laser is 1.500mrad. The result is only 0.186% affected by the error, which verifies the feasibility of the measurement method and the high-precision measurement of laser beam pointing stability by the system.