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 in transverse (X and Y) directions is accomplished in a mechanically simple and fast-responding manner. Closely adjacent to the objective lens assembly of the delivery system is a pair of prisms, i.e. a Risley prism or Herschel prism, positioned on the axis of the approaching laser beam. The two prisms, closely spaced, are mounted on separate rotating stages whereby they may be individually rotated about the beam axis. When the prisms are co-rotated, circular scans are produced on the target, in diameters depending on the angular phase between the prisms. Counter rotation of the prisms at equal and opposite speeds will produce a diametric line scan on the target. Any desired complex scan pattern can be achieved using combinations of rotations of the two 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.