BISMUTH-SUBSTITUTED RARE EARTH IRON GARNET CRYSTAL FILM AND OPTICAL ISOLATOR

• Main Authors: NOMI, Yasutaka, OOSUMI, Shuuji, NAKAMURA, Nobuo, HATANAKA, Hiroshi, KAJIGAYA, Tomio
• Format: Patent
• Language: English; French; German
• Published: 21.02.2018
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRICITY; FREQUENCY-CHANGING; INDUCTANCES; MAGNETS; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSFORMERS; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

[Object] To provide a bismuth-substituted rare-earth iron garnet crystal film (RIG) which has an insertion loss of less than 0.60 dB and which can be produced in a high yield, as well as an optical isolator. [Solving means] Provided is a bismuth-substituted rare-earth iron garnet crystal film which is grown by liquid phase epitaxy on a non-magnetic garnet substrate represented by a chemical formula of Gd 3 (ScGa) 5 O 12 , wherein the bismuth-substituted rare-earth iron garnet crystal film is represented by a chemical formula of La 3-x-y Gd x Bi y Fe 5 O 12 (provided that 0<x<3 and 0<y<3), and a composition ratio between the La, Gd, and Bi falls within a numeric value range corresponding to the inside of a quadrilateral having composition points A, B, C, and D as vertices in a La-Gd-Bi ternary composition diagram: composition point A (La: 0.15, Gd: 1.66, Bi: 1.19), composition point B (La: 0.32, Gd: 1.88, Bi: 0.80), composition point C (La: 0.52, Gd: 1.68, Bi: 0.80), and composition point D (La: 0.35, Gd: 1.46, Bi: 1.19).