Abstract: A cold storage material having a large thermal capacity in a ultra-low temperature range of 10 K or less and being highly durable against thermal shock and mechanical vibration. The cold storage material contains a rare earth oxysulfide ceramic represented by the general formula R2O2S in which R is one or more kinds of rare earth elements selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and Al2O3 having a specific surface area of 0.3 m2/g to 11 m2/g is added to the cold storage material.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a highlight transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and includes Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and includes Si and Lu as sintering aids.

Abstract: Provided is a ceramic composition capable of achieving a light scattering function while maintaining optical properties at a high level. The ceramic composition comprises a fluorescence phase comprising a fluorescent material and a light-scattering phase comprising a lanthanum oxide. The lanthanum oxide may be, for example, at least one selected from LaAlO3 and La2O3. The ratio of the fluorescent material (or the fluorescence phase) to the lanthanum oxide (or the light-scattering phase), the former/the latter, may be 99.9/0.1 to 50/50 in terms of volume ratio.

Abstract: Provided is a cold storage material having a large thermal capacity in a ultra-low temperature range of 10 K or less and being highly durable against thermal shock and mechanical vibration. The cold storage material contains a rare earth oxysulfide ceramic represented by the general formula R2O2S (wherein R is one or more kinds of rare earth elements selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y), and Al2O3 having a specific surface area of 0.3 m2/g to 11 m2/g is added to the cold storage material.

Abstract: Provided is a ceramic composition capable of achieving a light scattering function while maintaining optical properties at a high level. The ceramic composition comprises a fluorescence phase comprising a fluorescent material and a light-scattering phase comprising a lanthanum oxide. The lanthanum oxide may be, for example, at least one selected from LaAlO3 and La2O3. The ratio of the fluorescent material (or the fluorescence phase) to the lanthanum oxide (or the light-scattering phase), the former/the latter, may be 99.9/0.1 to 50/50 in terms of volume ratio.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a highlight transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and includes Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and includes Si and Lu as sintering aids.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a high light transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and comprises Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and comprises Si and Lu as sintering aids.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a high light transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and comprises Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and comprises Si and Lu as sintering aids.

Abstract: There is provided a rare-earth gallium garnet ceramic having a high extinction ratio and a high light transmittance. The rare-earth gallium garnet ceramic contains, as a sintering aid, 5 mass ppm or more and 500 mass ppm or less of Ge calculated as metal, and 20 mass ppm or more and 250 mass ppm or less of Al calculated as metal.

Abstract: There is provided a rare-earth gallium garnet ceramic having a high extinction ratio and a high light transmittance. The rare-earth gallium garnet ceramic contains, as a sintering aid, 5 mass ppm or more and 500 mass ppm or less of Ge calculated as metal, and 20 mass ppm or more and 250 mass ppm or less of Al calculated as metal.

Abstract: The present invention provides a lutetium oxide sinter to which yttrium is added in an amount of 100 mass ppm to 7000 mass ppm, whose average particle size is from 0.7 to 20 ?m, and with which there is no precipitation of a hetero phase containing yttrium at the grain boundary.

Abstract: As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed.

Abstract: The present invention provides a lutetium oxide sinter to which yttrium is added in an amount of 100 mass ppm to 7000 mass ppm, whose average particle size is from 0.7 to 20 ?m, and with which there is no precipitation of a hetero phase containing yttrium at the grain boundary.

Abstract: As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed.

Abstract: As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed.

Abstract: As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed.

Abstract: A TAG, LAG or YbAG anti-corrosion layer of which Si content is 100 ppm or under and total content of Ca and Mg is 200 ppm or under is provided on the internal surface of a tubular YAG base of a discharge envelope. The mean particle size of the anti-corrosion layer is 20 &mgr;m or over, and the mean particle size of the base is 15 &mgr;m or under.