Optimization design of two-group night vision zoom lenses

An optimization design for mechanically compensated two-group zoom lenses for night vision applications is presented. Two optimization algorithms combined with a merit function and the damped least-squares method are proposed and used for optimization of each lens-group. This optical lens design should be good enough to meet the performance requirements for an image intensifier tube. The proposed zoom system consists of a negative and a positive lens-group structure with one aspheric lens and seven glass lenses. The design result of zoom lenses includes spectral range of 600-900 nm, focal length range of 12-35 mm, zoom ratio of 2.9, the maximum full-field angle of 74° and f-number of 1.9-2.3. The total length of the zoom system is less than 200 mm. The design results show that the best performance can be obtained by our proposed approach.