Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of more than 1000 mass ppm and 2000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 550° C. or more and 600° C. or less, to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 1×1010 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 450° C. or more and less than 500° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 1×1010 ?·cm or less.

Abstract: To provide a method of producing a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and also variations in volume resistivity are small among substrates machined from the same ingot. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which a lithium niobate single crystal having a Fe concentration of 50 mass ppm or more and 2000 mass ppm or less in the single crystal and being in a form of an ingot is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 450° C. or more and less than 660° C., which is a melting point of aluminum, to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 2×1012 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 350° C. or more and less than 450° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of more than 1×1010 ?·cm to 2×1012 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 350° C. or more and less than 450° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of more than 1×1010 ?·cm to 2×1012 ?·cm or less.

Abstract: To provide a method of producing a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and also variations in volume resistivity are small among substrates machined from the same ingot. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which a lithium niobate single crystal having a Fe concentration of 50 mass ppm or more and 2000 mass ppm or less in the single crystal and being in a form of an ingot is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 450° C. or more and less than 660° C., which is a melting point of aluminum, to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 2×1012 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of more than 1000 mass ppm and 2000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 550° C. or more and 600° C. or less, to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 1×1010?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of more than 1000 mass ppm and 2000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 450° C. or more and less than 550° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of more than 1×1010 ?·cm to 2×1012 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 450° C. or more and less than 500° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×108 ?·cm or more to 1×1010 ?·cm or less.

Abstract: To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al2O3, and heat-treated at a temperature of 350° C. or more and less than 450° C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of more than 1×1010 ?·cm to 2×1012 ?·cm or less.

Abstract: 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, which is grown by liquid phase epitaxy on a non-magnetic garnet substrate represented by a chemical formula of Gd3(ScGa)5O12, wherein the bismuth-substituted rare-earth iron garnet crystal film is represented by a chemical formula of La3-x-yGdxBiyFe5O12 (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).

Abstract: A bismuth-substituted rare-earth iron garnet crystal film (RIG) which has an insertion loss of less than 0.6 dB and which can be produced in a high yield, as well as an optical isolator, which is grown by liquid phase epitaxy on a non-magnetic garnet substrate represented by a chemical formula of Gd3(ScGa)5O12, wherein the RIG is represented by a chemical formula of Nd3-x-yGdxBiyFe5O12, and x and y satisfy 0.89?x?1.43 and 0.85?y?1.19. In contrast to conventional RIGs, the RIG represented by the chemical formula of Nd3-x-yGdxBiyFe5O12 of the present invention has an insertion loss of less than 0.6 dB and makes it possible to reduce the amount of heat generated because of absorption of light at wavelengths of about 1 ?m. Hence, the RIG has such a remarkable effect that the RIG can be used as a Faraday rotator used for an optical isolator in a high-power laser device for processing.

Abstract: [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 Gd3(ScGa)5O12, wherein the bismuth-substituted rare-earth iron garnet crystal film is represented by a chemical formula of La3-x-yGdxBiyFe5O12 (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.

Abstract: [Object] To provide a bismuth-substituted rare-earth iron garnet crystal film (RIG) which has an insertion loss of less than 0.6 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 Gd3(ScGa)5O12, wherein the RIG is represented by a chemical formula of Nd3-x-yGdxBiyFe5O12, and x and y satisfy 0.89×1.43 and 0.85?y?1.19. In contrast to conventional RIGs, the RIG represented by the chemical formula of Nd3-x-yGdxBiyFe5O12 of the present invention has an insertion loss of less than 0.6 dB and makes it possible to reduce the amount of heat generated because of absorption of light at wavelengths of about 1 ?m. Hence, the RIG has such a remarkable effect that the RIG can be used as a Faraday rotator used for an optical isolator in a high-power laser device for processing.

Abstract: A lithium tantalate substrate obtained by working in the state of a substrate a lithium tantalate crystal grown by the Czochralski method is buried in a mixed powder of Al and Al2O3, followed by heat treatment carried out at a temperature kept to from 350 to 600° C., to manufacture a lithium tantalate substrate having volume resistivity which has been controlled within the range of from 1010 to 1013 ?cm. The substrate obtained has a very low pyroelectricity or no pyroelectricity, and it can be made colored and opaque from a colorless and transparent state and also sufficiently has the properties required as a piezoelectric material.

Abstract: A lithium tantalate substrate obtained by working in the state of a substrate a lithium tantalate crystal grown by the Czochralski method is buried in a mixed powder of Al and Al2O3, followed by heat treatment carried out at a temperature kept to from 350 to 600° C., to manufacture a lithium tantalate substrate having volume resistivity which has been controlled within the range of from more than 108 to less than 1010 ?cm. The substrate obtained has no pyroelectricity, and it can be made colored and opaque from a colorless and transparent state and also sufficiently has the properties required as a piezoelectric material.

Abstract: A lithium tantalate substrate obtained by working in the state of a substrate a lithium tantalate crystal grown by the Czochralski method is buried in a mixed powder of Al and Al2O3, followed by heat treatment carried out at a temperature kept to from 350 to 600° C., to manufacture a lithium tantalate substrate having volume resistivity which has been controlled within the range of from more than 108 to less than 1010 ?cm. The substrate obtained has no pyroelectricity, and it can be made colored and opaque from a colorless and transparent state and also sufficiently has the properties required as a piezoelectric material.

Abstract: In a process for manufacturing a LT substrate from a LT crystal, after growing the crystal, a LT substrate in ingot form is imbedded in carbon power, or is place in a carbon vessel, and heat treated is conducted at a maintained temperature of between 650° C. and 1650° C. for at least 4 hours, whereby in a lithium tantalate (LT) substrate, sparks are prevented from being generated by the charge up of an electric charge on the substrate surface, and thereby destruction of a comb pattern formed on the substrate surface and breaks or the like in the LT substrate are prevented.

Abstract: In a process for manufacturing a LT substrate from a LT crystal, after growing the crystal, a LT substrate in ingot form is imbedded in carbon power, or is place in a carbon vessel, and heat treated is conducted at a maintained temperature of between 650° C. and 1650° C. for at least 4 hours, whereby in a lithium tantalate (LT) substrate, sparks are prevented from being generated by the charge up of an electric charge on the substrate surface, and thereby destruction of a comb pattern formed on the substrate surface and breaks or the like in the LT substrate are prevented.

Abstract: In a process for manufacturing a LT substrate from a LT crystal, after growing the crystal, a LT substrate in ingot form is imbedded in carbon power, or is place in a carbon vessel, and heat treated is conducted at a maintained temperature of between 650° C. and 1650° C. for at least 4 hours, whereby in a lithium tantalate (LT) substrate, sparks are prevented from being generated by the charge up of an electric charge on the substrate surface, and thereby destruction of a comb pattern formed on the substrate surface and breaks or the like in the LT substrate are prevented.