SINGLE CRYSTAL OF LITHIUM NIOBATE AND OPTICAL ELEMENT

• Main Authors: NITANDA FUMIO, FURUKAWA YASUNORI, SATO MASAZUMI, ITO KOHEI
• Format: Patent
• Language: English
• Published: 27.04.1993
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; DEVICES USING STIMULATED EMISSION; ELECTRICITY; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PURPOSE:To obtain single crystal of lithium niobate having excellent light damage resistance by adding a specific element such as Y or lanthanide to single crystal of lithium niobate. CONSTITUTION:Single crystal of lithium niobate containing one or more of Y, lanthanide and elements of the group IIIB of the periodic table. The reason why light damage resistance strength of single crystal is extremely improved is considered as follows. Namely, single crystal of lithium niobate is mixed with element of group IIIA and IIIB, these elements form a shallow impurity level in the crystal. When light rays are passed into crystal, electrons are excited from the impurity level and increase in light conductivity of crystal causes rise in light damage resistance strength. Shielding or attenuation of an inner electric field made by electrons of Fe<3+> excited is considered to be a main factor of the extreme improvement of light damage resistance strength.