Optical design of ultraviolet continuous zoom lens for sulfur dioxide remote sensing monitoring

In order to meet the needs of high-definition imaging of atmospheric sulfur dioxide remote sensing monitoring at different distances, a continuous zoom ultraviolet lens was designed. Based on the theoretical analysis of Gaussian optical solution of zoom system, four groups of positive compensation mechanical zoom initial structure were selected, three intervals of zoom group solution of two-group mechanical compensation zoom system were calculated, and the power distribution of zoom group and compensation group was obtained. According to the absorption characteristics of atmospheric sulfur dioxide to ultraviolet light, the working band was determined to be 250 nm~340 nm. An ultraviolet continuous zoom optical system with zoom ratio of 10, F number of 4 and total length of 431.5 mm was designed by using Zemax optical design software, and the motion curves of zoom group and compensation group were drawn by using Matlab software. The focal length range of the system is 25 mm~250 mm, the short focal field range is 0°~7.67°, the medium focal field range is 0°~1.45°, and the telephoto field range is 0°~0.77°. During zoom process, the transfer function is greater than 0.3 at 107 lp/mm, the distortion is less than 1%, and the radius of the speckle is less than 5.5 μm. This system is suitable for monitoring sulfur dioxide in various scenarios, such as ship exhaust, industrial production chimney exhaust and so on.