Dual FOV Afocal Zoom System with Stationary Pupils Using Single Moving Group

摘要

Afocal lenses are often one part of a more complex optical system and are widely used to couple two infinity corrected optical subsystems (typically with different apertures and fields of view) together. One major concern for such an application is the pupil mismatch between the subsystems which degrades the system performance by introducing resolution and illumination loss at the edge of the field. This issue becomes even more apparent in an afocal zoom system, where the pupil locations usually vary as a function of zoom position. In this paper, formulae and design examples are demonstrated for designing a novel type of afocal zoom system that has two discrete zoom positions with stationary and accessible real entrance and exit pupils. The variation of field of view, while maintaining image plane and pupil locations are achieved simultaneously with only one moving group. The design space was explored with a first order analysis to validate different design forms. Design examples are shown for the only two possible design forms that resulted.