LITHIUM TANTALATE SINGLE CRYSTAL, ITS PRODUCTION AND OPTICS

摘要

PURPOSE:To provide the subject lithium tantalate single crystal excellent in optical damage resistance properties and to provide the subject optics made of the single crystal. CONSTITUTION:One of this inventions is a lithium niobate single crystal produced by the double crucible method, the LPE method or the gas phase growth method and characterized by the excellent optical damage resistance due to its crystal composition containing Li component in an amount lower than the congruent composition and exhibiting a molar fraction represented by [(Li2 O)/(Li2O+Nb2O5)] within a range of >0.45 and <0.486. An invention is to prepare a thin film made of this single crystal. The other invention is to provide an SHG element capable of generating the second harmonic by passing laser light as the fundamental wave emitted from a laser source made of this single crystal or the thin film through a non-linear optical crystal.