SYSTEM FOR SCANNING A SURGICAL LASER BEAM

摘要

In a laser beam delivery system for a surgical laser beam, steering and scanning of the laser beam along the target (20) in transverse (X and Y) directions is accomplished in a mechanically simple and fast-responding manner. Closely adjacent to the objective lens assembly (24) of the delivery system is a pair of prisms (12, 14), i.e. a Risley prism or Herschel prism, positioned on the axis (16) of the approaching laser beam (18). The two prisms are mounted on separate rotating stages whereby they may be individually rotated about the beam axis. Co-rotation of the prisms produces circular scans, in diameters depending on the angle between the prisms. Counter rotation of the prisms at equal speeds will produce a diametric line scan. Any desired complex scan pattern can be achieved using combinations of rotations of the prisms. Axial compactness and proximity to the objective lens assembly assure that virtually all of the angularly emerging beam from the prism pair passes through the objective lens assembly.