METHOD FOR DESIGING OFF-AXIAL THREE-MIRROR OPTICAL SYSTEM WITH FREEFORM SURFACES

摘要

A method for designing off-axial three-mirror optical system with freeform surfaces is provided. A first initial surface, a second initial surface, and a third initial surface are established. A plurality of feature rays are selected, while the first initial surface and the third initial surface remain unchanged; a plurality of first feature data points are calculated to obtain a third freeform surface equation by surface fitting the plurality of first feature data points. A third freeform surface and the second initial surface are remained unchanged; a plurality of second feature data points are calculated to obtain a first freeform surface equation by surface fitting the plurality of second feature data points. The third freeform surface and a first freeform surface are remained unchanged; a plurality of third feature data points are calculated to obtain a second freeform surface equation by surface fitting the plurality of third feature data points.

主权项

1. A method for designing an off-axial three-mirror optical system with freeform surfaces comprising:
step (S1), establishing an initial system, the initial system comprises a first initial surface, a second initial surface, and a third initial surface; wherein the first initial surface, the second initial surface, and the third initial surface are separated from each other; step (S2), keeping the first initial surface and the second initial surface unchanged; selecting a plurality of feature rays Ri (i=1,2 . . . K); and calculating a plurality of first feature data points point by point based on a given object-image relationship and Snell's law to obtain a third freeform surface equation by surface fitting the plurality of first feature data points; step (S3), keeping a third freeform surface and the second initial surface unchanged; and calculating a plurality of second feature data points point by point based on the given object-image relationship and Snell's law to obtain a first freeform surface equation by surface fitting the plurality of second feature data points; and step (S4), keeping the third freeform surface and a first freeform surface unchanged; and calculating a plurality of third feature data points point by point based on the given object-image relationship and Snell's law to obtain a second freeform surface equation by surface fitting the plurality of third feature data points.