Abstract: A laser crystal for a solid state laser with tunable emission in the ultraviolet wavelength region. The crystal is of trivalent cerium cations activated (doped) into the colquiriite crystal structures, such as LiCaAlF.sub.6 (LiCAF) and LiSrAlF.sub.6 (LiSAF). The crystal is grown along a well-defined axis by seeded crystal growth techniques to provide starting material which is fabricated along the preferred polarization direction with high yields. A primary crystal growth issue for cerium activated colquiriites is the charge compensation mandated by the substitution of the trivalent cerium ion for divalent strontium, which is located in the only site large enough to support the cerium cation. Charge compensation with monovalent or divalent cations is utilized to optically stabilize the colquiriite crystal and produce a solid state laser host which is less susceptible to color center or optically-induced defect formation during the ultraviolet lasing or ultraviolet excitation mechanisms.

Abstract: An optic positioning device for holding an optical element which has a center and for adjustng the optical element relative to its center. The optic positioning device includes a supporting base which has an upwardly facing concave spherical surface and a holding body for supporting the optical element. The holding body has a downwardly facing spherical surface which is slidably mounted on the concave spherical surface of the supporting base. The radial centers of the concave and convex spherical surfaces are at the center of the optical element.

Abstract: A drum is mounted to rotate about its drum axis. A pair of elongated, complementary guides are proximate to and extend along the axial length of the drum. The guides are sized and spaced to allow a workpiece to span the guides and roll upon them. A driver is mounted alongside the guides for rolling the workpiece on them. These guides are positioned between the drive means and the drum. The workpiece is positionable between the driver and the guides to protrude beyond the guides and reach the drum.