Design and simulation of fluorescence acquisition optical path of sulfur dioxide based on ZEMAX

In order to realize the accurate and continuous detection of SO₂ in air by SO₂ analyzer, and solve the problems of weak light convergence effect, large aberration and longer optical path of fluorescence acquisition due to the lengthening of focal length of lens in traditional sulfur dioxide detector when fluorescence converges, on the basis of traditional instruments, the optical path of fluorescence acquisition was redesigned and optimized. The method of decomposition of light focus was used to improve the spherical aberration of the system. Theoretical analysis and experimental verification were carried out. After the improvement, ZEMAX simulation was carried out and orthogonal method was used to correct the new optical path. By simulating the non-sequential structured shadow model of two light paths, the illumination map of the detection viewer and the point chart, experimental data of light intensity and spot diameter were obtained. The results show that, the peak-to-radial intensity of the optimized optical system reaches 219.41W/cm². The diameter of the speckle is reduced by 17%. This scheme can effectively solve the shortcomings of traditional optical path and the imaging quality is better.