Abstract: Crystal housing apparatus for adjustably positioning cooperating non-linear optical crystals in a laser beam generating system, includes a housing (50) with entry (60) and exit (62) windows for respective laser beams, respective holder means (72, 74, 76) to retain respective crystals within the housing in optical alignment with the windows, and means (86) mounting the respective holder means for individual fine rotational adjustment of the crystals about respective axes. Individual temperature control elements (120) are mounted in association with the respective holder means for controlling the temperature of the respective crystals and means (110, 114) is provided for effecting the fine rotational adjustment of the crystals.

Abstract: The present invention provides a method for scanning material with a laser beam including directing a laser beam (20) through a scanning means, wherein said scanning means includes a first lens (11) and a second lens (12) separated by a distance (16) approximately equal to the focal length of the lenses. The method includes controlling the beam (20) by moving at least one of the lenses in a plane perpendicular to the beam to scan the material. The invention also provides a scanning apparatus for scanning material with a laser beam including laser means for producing a beam of ultraviolet or infra-red light, scanning means for scanning the laser source in a predetermined pattern onto an area of the material, and controlling means for controlling the scanning means, wherein the scanning means includes two lenses, separated by approximately the focal length of one of the lenses, with at least one of the lenses movable perpendicular to the beam to scan the beam.