A denoising method based on multiple-stage acousto-optic tunable filter in the green laser measurement system

Abstract The charge handling capacity of CCD camera is limited, so image distortion is caused by bright light generated by the hot workpiece. The green laser stripe captured by CCD camera is fuzzy in the green laser measurement system. In order to make the image of the stripe clearer, the filter system is designed based on multiple-stage acousto-optic tunable filter. In the filter system, a computational model is built by combining the visible radiation character of hot workpiece and the threshold power density of CCD saturation. The curve of the filtering rate of bright light can be obtained using the computational model. In order to realize the goal of intelligent filter, each stage of the acousto-optic tunable filter is adjusted according to the curve of the filtering rate. Finally, the image of green laser stripe on hot workpiece is clearer. The filter system designed in the paper is viable according to the experiment results. And the accuracy of the green laser measurement system is improved.