Five mirror, two perpendicular plane image derotator

摘要

An image derotator (10) uses five or a higher odd number of) mirrors mounted in two perpendicular planes. When used in scanning systems (14) that result in image rotation, the derotator (10) will derotate the image, thereby maintaining a constant image orientation. In addition, the derotator (10) permits a controlled amount of polarization sensitivity to be achieved, by adjusting the angles between the mirrors. Zero polarization sensitivity can also be achieved by proper adjustment of mirror angles.