title: Vapor-transport equilibrated near-stoichiometric lithium tantalate for frequency-conversion applications.
abstract: Near-stoichiometric lithium tantalate (SLT) crystals were produced from congruent lithium tantalate by a vapor-transport equilibration process. Because of the resultant increase in photoconductivity and reduction in photogalvanism, the crystals showed no observable photorefractive damage at 514.5 nm up to the highest intensity used, 2 MW/cm2. The crystals also exhibited low green-induced infrared absorption, a Curie temperature of 693 degrees C, and a coercive field of 80 V/mm. The SLT samples were periodically poled with an 8-microm-period grating, permitting first-order quasi-phase-matched second-harmonic generation of 532-nm radiation at 43 degrees C. A 17-mm-long sample generated 1.6 W of continuous-wave output power at 532 nm for 50 h. With 150-ns pulses at a 100-kHz repetition rate in the same sample, 5-W average-power, 532-nm radiation was generated for 1000 h. No damage to the crystal and no aging effects were observed during these experiments.
authors.affiliation: E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088, USA. moti@soreq.gov.il
authors.forename: M
authors.initials: M
authors.lastname: Katz
authors.forename: R K
authors.initials: RK
authors.lastname: Route
authors.forename: D S
authors.initials: DS
authors.lastname: Hum
authors.forename: K R
authors.initials: KR
authors.lastname: Parameswaran
authors.forename: G D
authors.initials: GD
authors.lastname: Miller
authors.forename: M M
authors.initials: MM
authors.lastname: Fejer