| 摘要 |
An infra-red optical system, such as an afocal telescope, having a beam-splitter plate located in a beam position having one valve of numerical aperture and tilted with respect to the optical axis has a single compensating plate located in a beam position having a different value of numerical aperture and tilted differently with respect to the optical axis so as to compensate for aberrations introduced by the tilted beam-splitter plate. The beam-splitter and compensating plates are preferably tilted about respective first and second axes orthogonal to the optical axis and lying on mutually orthogonal planes.
|
