| 摘要 |
<p>An optical steering assembly includes first and second steering elements (105, 111) for redirecting light in both forward and return optical paths without crosstalk. Input light traveling in the first direction (7a) is directed from the first side (61a) of the first element to the first side (71a) of the second element, undergoing two orthogonal steering deflections to a redirected output path (8a). Return light along the same or a closely adjacent path (8b) is directed at the second side (61b) of one element, to the second side (71b) of the other element. The return light strikes the opposite sides of the same elements as the input light, and undergoes corresponding steering corrections while maintaining complete beam separation. The assembly is especially useful in instruments where low light levels, scan distortion, or crosstalk would otherwise limit performance. A two dimensional fundus tracker (700) employs one such assembly (750) as an objective steering system for all illumination, and two further assemblies (721, 722) for positioning tracking beams directed into the objective steering system.</p> |
