Abstract: Crystals of lithium niobate and lithium tantalate are preconditioned to intentionally increase their electrical conductivity, thus providing crystals with an increased ability to reduce surface charging. Reducing surface charging reduces the risk that the crystals may catastrophically discharge, and adversely affect the performance of devices in which the crystal is incorporated.

Abstract: A new compositional relationship in the starting charge of a crystal growth station (FIG. 1 ) provides homogeneous monocrystalline lithium niobate. A new measurement system (FIG. 2 ) provides Curie point values of significantly greater accuracy then that of conventional measurements. Careful control of the starting charge composition for crystal growth and effective utilization of the measurement system enable the determination of the compositional range of starting charges for producing congruent crystalline production. The composition corresponds to a mol percentage of 48.35.+-..01 to 48.40.+-..01 of Li.sub.2 O and the remainder Nb2.sub.O 5 for producing homogeneous crystal whose solidification fraction of the molten charge exceeds that which was heretofore achievable.

Abstract: An optical element composed of a single crystal consisting essentially of potassium titanyl phosphate, which is represented by the formula KTiOPO.sub.4 and which is doped with cerium. The optical element has a high optical transmissivity property for radiation from the near-UV to the mid-infrared spectral regions.