Overview of beam steering technology based on rotational double prisms

The rotational-double-prism system can change the optical path by rotating separately the two prisms of a common axis,so that it can be used to steer the beams or the Line of Sight(LOS).Compared with the conventional two-axis or three-axis optical electro-optical gimbals,the rotational-double-prism-based beam or LOS steering devices offer tremendous advantages such as high accuracy,compactness and good dynamic performance,and have been proved to be the helpful complementarity for electro-optical gimbals.This paper analyzes the beam steering mechanism of the rotational-double-prism system,and introduces the key problems of the relevant theories for the beam steering,which focus on the beam deflection mechanism,beam scanning mode,prism rotation control,beam deformation,imaging aberration and the imaging distortion induced by a prism.It describes the research progress of engineering technology and gives several kinds of products based the rotational-double-prism system and their application to the laser beam steering and target searching,target recognition and traking imaging.Finally,the technical challenges concluded in scanning patterns,beam quality,chromatic aberration,image distortions and rotation control are discussed and the development trends are evaluated.