Ultra wide band achromatic Risley prism scanner

摘要

A system and method for scanning a wide band beam is presented. An apparatus includes a pair of prism triplets. Each prism triplet includes a first wedge prism, a second wedge prism and a third wedge prism all formed with different optical materials. In operation, a beam passing through the wide band team scanning apparatus first passes through the first, second and third wedge prisms of the first prism triplet. The beam then passes through the wedge prisms of the second prism triplet in a mirrored order (the third, then second, then first wedge prisms) than that of the first prism triplet. This apparatus with two prism triplets allows wide band light transmitted through it to emerge with its plurality of different wavelengths of light travelling in the same direction to equalize net dispersive effects each of different wavelengths.

主权项

1. A wide band beam scanning apparatus comprising:
a pair of prism triplets comprising a first prism triplet and a second prism triplet, wherein the first prism triplet and the second prism triplet both include a first wedge prism, a second wedge prism and a third wedge prism, wherein the first wedge prism and the second wedge prism are formed with different optical materials; wherein components of the wide band beam scanning apparatus are arranged so that a beam passing through the wide band beam scanning apparatus first passes through the first wedge prism of the first prism triplet, then the second wedge prism of the first prism triplet, then the third wedge prism of the first prism triplet, then the third wedge prism of the second prism triplet, then the second wedge prism of the second prism triplet and then the first wedge prism of the second prism triplet; wherein the second prism triplet is rotated 180 degrees about a center point with respect to the first prism triplet so that the wide band beam scanning apparatus is configured to have a beam exiting the third wedge prism of the first prism triplet and next enter the third wedge prism of the second prism triplet before entering the first wedge prism of the second prism triplet; wherein the third angle is about 10 degrees, the second angle is about 40.3 degrees, and the first angle is about 13.95 degrees; wherein the first wedge prism is formed out of zinc sulfide (ZnS), the second wedge prism is formed out of zinc selenide (ZnSe) and the third wedge prism is formed out of gallium arsenide (GaAs).