Patent ID: 7982983

Claim:
A beam steering apparatus comprising: a Risley double-prism pair, including: a first double-prism comprising a first prism made of a first material and a second prism made of a second material, the first and second materials having different refractive indices, each of the first and second prisms having one side joined to the other prism of the double-prism along an optical path, where one of the first and second materials includes As x S y or As x Se y ; a second double-prism spaced from the first double-prism along the optical path and comprising a third prism made of a third material and a fourth prism made of a fourth material, the third and fourth materials having different refractive indices, each of the third and fourth prisms having one side joined to the other prism of the second double-prism along the optical path; a first rotatable support structure operative to rotate the first double-prism about the optical path; a second rotatable support structure operative to rotate the second double-prism about the optical path; and a controller operatively coupled with the first and second rotatable support structures to control independent or joint rotation of the first and second double-prisms to steer a beam entering the apparatus along the optical path.