Laser Beam Quality Analysis And Detection System Based On Two Points

This paper describes the development of a laser beam quality analysis and detection system which based on the two-point method. The system designed for accurately testing the lasers of little power and small divergence angle.In this paper, the laser beam quality analysis theory and the characteristics of the Gaussian beam is expounded, through comparing to the traditional test and analysis methods, this paper puts forward a method based on two-point method for laser beam quality analysis and detection, according to the theory derivation of measurement principle designed the detection system. This system uses CCD device as the main detector, to realize the measurement of far field and divergence angle, and design components for increasing optical path. Using polarizer for light intensity attenuation, continuous adjustment laser power density according to the different product, to ensure CCD output both higher and not saturated. Use the grating scale to measure the position deviation, improved the displacement detection accuracy. And design the servo structure of the polarizer and CCD camera movement. Integrated uses moire fringe counting, precise screw transmission, worm gear and worm drive, motor stepping control technology to achieve precise motion control.PC software developed by using the object-oriented programming software, realized the CCD flare data and grating displacement data collection, treatment, calculation, analysis and the step motor control, the interface intuitive and friendly. The result of experiment shows that this system is high precision, high measurement speed and high degree of automation.