User:IhtshamUlHaq325inWiki/Risley prism

Risley prism: Risley prism comprises two prisms/wedge-prisms placed planar side parallel to each other – used for deviating and steering the beam to target specimen. The component prism is just like right-angle prism but having two perpendicular sides of unequal length. Usage: When two risley prism are placed side by side such that hypotenuse side are away from each other and the longer side among the other two sides are just in front of each other. Then this setup can be used for beam steering to any deviation (obviously upto some limit) and diretion about optical-axis. When arranged in a form to have net thickness same over all(i.e narrower-edge with broader, and broader-edge with narrower), then it behaves as a refracting glass-slab and the beam donot deviate angularly but only displaces. Whereas its maximum deviation occurs if they are arranged oppositely(narrower-edge with narrower, and broader-edge with broader). In between deviations are set by intermediate rotations. Once they are deviated upto certain degiation-angle, then they are directed to the target/specimen. So this can be more easily used for beam-steering.

Acknowledgments: Thanks to Ihtram-ul-Haq(KU)