Abstract: [Problem] The present invention relates to a magnetic garnet single crystal prepared by the liquid phase epitaxial (LPE) process and an optical element using the same as well as a method of producing the single crystal, for the purpose of providing a magnetic garnet single crystal at a reduced Pb content and an optical element using the same, as well as a method of producing the single crystal. [Means for Resolution] The magnetic garnet single crystal is grown by the liquid phase epitaxial process and is represented by the chemical formula BixNayPbzM13-x-y-zFe5-wM2wO12 (M1 is at least one element selected from Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and M2 is at least one element selected from Ga, Al, In, Ti, Ge, Si and Pt, provided that 0.5<x?2.0, 0<y?0.8, 0?z<0.01, 0.19?3?x?y?z<2.5, and 0?w?1.6).

Abstract: A of producing a magnetic garnet material of which the light absorption characteristics worsen little even though it is produced through LPE. The crucible for LPE is formed of a material containing Au. The amount of Au to be taken in single crystal formed in an Au crucible is smaller than that of Pt to be taken therein formed in a Pt crucible. As compared with Pt, the influence of Au on magnetic garnet film that increases the insertion loss in the film is small.

Abstract: The invention relates to a method of producing an optical element using a garnet single crystal for the purpose of providing an optical element with a reduced Pb content or from which Pb can preliminarily be removed completely. By growing a garnet single crystal by using a solution containing Na, Bi and B by the LPE process and thermally treating the garnet single crystal in reducing atmosphere prepared by using nitrogen gas and/or hydrogen gas, the resulting thermally treated garnet single crystal is used to prepare an optical element.

Abstract: The invention relates to a magnetic garnet single crystal and an optical element using the same, for the purpose of providing a magnetic garnet single crystal at a reduced Pb content, and an optical element using the same, where the magnetic garnet single crystal is represented by the chemical formula Bi?M13-?Fe5-?-?M2?M3?O12 (M1 is at least one element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and M2 is Si; and M3 is at least one element selected from Zn, Ni, Cu and Mg, provided that 0.5<??2.0, 0<?, and 0<y).

Abstract: It is an object of the present invention to provide a magnetic garnet single crystal at a reduced Pb content, and a method for producing the same and an optical element using the same. The object is attained with a magnetic garnet single crystal represented by the chemical formula Bi?Na?M13-?-?Fe5-?M2?O12 (M1 is at least one element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and M2 is at least one element selected from Si, Ge and Ti, provided that 0.5<??2.0, 0<??0.8, 0.2?3????<2.5, and 0<??1.6).

Abstract: A hard magnetic Bi-substituted rare earth iron garnet material with excellent Faraday rotary moment, temperature property, wavelength property and insertion loss is provided. A Bi-substituted rare earth iron garnet material having a chemical composition of (Bi3-a-b-cGdaTbbYbc) Fe(5-w)MwO12 (where, M is at least one element selected from the group consisting of Ga, Al, Ge, Sc, In, Si and Ti, 0.5?a+b+c?2.5, 0.2?w?2.5) can be provided with hard magnetism and have excellent Faraday rotary moment, temperature property, wavelength property and insertion loss.

Abstract: There are provided a manufacturing method of an optical device excellent in expediency, and a technique for stably manufacturing a high performance optical device. After a single crystal film which constitutes a Faraday rotator and can exhibit a substantially rectangular magnetic hysteresis, is obtained, the single crystal film is magnetized in a state where this single crystal film is incorporated in an optical device such as an optical isolator. By performing a magnetizing step after the Faraday rotator is incorporated in the optical device, it becomes unnecessary to discriminate between the front and back surfaces of the single crystal film, and the characteristics of the optical device are also improved.

Abstract: There are provided a manufacturing method of an optical device excellent in expediency, and a technique for stably manufacturing a high performance optical device. After a single crystal film which constitutes a Faraday rotator and can exhibit a substantially rectangular magnetic hysteresis, is obtained, the single crystal film is magnetized in a state where this single crystal film is incorporated in an optical device such as an optical isolator. By performing a magnetizing step after the Faraday rotator is incorporated in the optical device, it becomes unnecessary to discriminate between the front and back surfaces of the single crystal film, and the characteristics of the optical device are also improved.

Abstract: Proposed is a technique of producing a magnetic garnet material of which the light absorption characteristics worsen little even though it is produced through LPE. The crucible for LPE is formed of a material containing Au. The amount of Au to be taken in single crystal formed in an Au crucible is smaller than that of Pt to be taken therein formed in a Pt crucible. As compared with Pt, the influence of Au on magnetic garnet film that increases the insertion loss in the film is small.

Abstract: Proposed is a technique of producing a magnetic garnet material of which the light absorption characteristics worsen little even though it is produced through LPE. The crucible for LPE is formed of a material containing Au. The amount of Au to be taken in single crystal formed in an Au crucible is smaller than that of Pt to be taken therein formed in a Pt crucible. As compared with Pt, the influence of Au on magnetic garnet film that increases the insertion loss in the film is small.

Abstract: A method of producing a magnetic garnet single crystal film formation substrate 2 for growing a magnetic garnet single crystal film by liquid phase epitaxial growth is provided. First, a base substrate 10 composed of a garnet-based single crystal being unstable with a flux used for the liquid phase epitaxial growth is formed. Next, a buffer layer 11 composed of a garnet-based single crystal thin film formed at least on a crystal growing surface of said base substrate 10 and being stable with the flux is formed. When forming the buffer layer 11 on the base substrate 10, it is formed by a thin film formation method, such as sputtering, without heating the substrate 10 in a positive manner.

Abstract: A magnetic garnet single crystal film formation substrate 2 for growing a thick magnetic garnet single crystal film, wherein crystal defects, warps, cracks and flaking, etc. are not caused, by liquid phase epitaxial growth is provided. The substrate 2 comprises a base substrate 10 composed of a garnet-based single crystal being unstable with a flux used for the liquid phase epitaxial growth; a buffer layer 11a composed of a garnet-based single crystal thin film formed on a crystal growing surface 10a of said base substrate 10 and being stable with said flux; and a protective layer 11b formed at least on side surfaces 10b of said base substrate 10 crossing with said crystal growing surface of said base substrate 10 and being stable with said flux. By using the substrate, a high quality magnetic garnet single crystal film can be produced.

Abstract: The invention relates to a Bi-substituted rare earth-iron garnet single-crystal film and a method for producing it, and also to a Faraday rotator comprising it. Its object is to provide a magnetic garnet single-crystal film which hardly cracks while it grows or is cooled or polished and worked, and to provide a method for producing it. Its object is also to provide a Faraday rotator produced at high yield by working the magnetic garnet single-crystal film which hardly cracks while it grows or is cooled or polished and worked. In a method for producing a magnetic garnet single-crystal film by growing a Bi-substituted magnetic garnet single crystal in a mode of liquid-phase epitaxial growth, the lattice constant of the growing magnetic garnet single crystal is so controlled that it does not vary or gradually decreases with the growth of the single-crystal film, and then increases with it.

Abstract: The invention relates to an optical device for polarizing light by changing its Faraday rotation angle, such as optical attenuators, optical switches or polarization controllers; and its object is to provide such an optical device which can be driven even by small-sized and power-saving magnetic circuits and in which the insertion loss in the Faraday rotator may be reduced. The optical device comprises a Faraday rotator formed of a garnet single crystal, and a magnetic circuit applying an external magnetic field H that is smaller than the saturation magnetic field Hs of the Faraday rotator to the Faraday rotator.

Abstract: A magnetic garnet single crystal film formation substrate for growing a magnetic garnet single crystal film by liquid phase epitaxial growth is provided. This substrate comprises a base substrate composed of a garnet-based single crystal which is unstable with a flux used for the liquid phase epitaxial growth and a buffer layer composed of a garnet-based single crystal thin film formed on the base substrate and being stable with said flux. A high-quality magnetic garnet single crystal film can be produced by using the substrate. The magnetic garnet single crystal film is used as an optical element, such as a Faraday element, used in an optical isolator, optical circulator and magneto-optical sensor, etc.

Abstract: A hard magnetic Bi-substituted rare earth iron garnet material with excellent Faraday rotary moment, temperature property, wavelength property and insertion loss is provided. A Bi-substituted rare earth iron garnet material having a chemical composition of (Bi3-a-b-cGdaTbbYbc) Fe(5-w)MwO12 (where, M is at least one element selected from the group consisting of Ga, Al, Ge, Sc, In, Si and Ti, 0.5≦a+b+c≦2.5, 0.2≦w≦2.5) can be provided with hard magnetism and have excellent Faraday rotary moment, temperature property, wavelength property and insertion loss.

Abstract: A hard magnetic Bi-substituted rare earth iron garnet material with excellent Faraday rotary moment, temperature property, wavelength property and insertion loss is provided. A Bi-substituted rare earth iron garnet material having a chemical composition of (Bi3−a−b−cGdaTbbYbc) Fe(5−w)MwO12 (where, M is at least one element selected from the group consisting of Ga, Al, Ge, Sc, In, Si and Ti, 0.5≦a+b+c≦2.5, 0.2≦w≦2.5) can be provided with hard magnetism and have excellent Faraday rotary moment, temperature property, wavelength property and insertion loss.

Abstract: Proposed is a technique of producing a magnetic garnet material of which the light absorption characteristics worsen little even though it is produced through LPE. The crucible for LPE is formed of a material containing Au. The amount of Au to be taken in single crystal formed in an Au crucible is smaller than that of Pt to be taken therein formed in a Pt crucible. As compared with Pt, the influence of Au on magnetic garnet film that increases the insertion loss in the film is small.

Abstract: There are provided a manufacturing method of an optical device excellent in expediency, and a technique for stably manufacturing a high performance optical device. After a single crystal film which constitutes a Faraday rotator and can exhibit a substantially rectangular magnetic hysteresis, is obtained, the single crystal film is magnetized in a state where this single crystal film is incorporated in an optical device such as an optical isolator. By performing a magnetizing step after the Faraday rotator is incorporated in the optical device, it becomes unnecessary to discriminate between the front and back surfaces of the single crystal film, and the characteristics of the optical device are also improved.

Abstract: The invention relates to an optical device for polarizing light by changing its Faraday rotation angle, such as optical attenuators, optical switches or polarization controllers; and its object is to provide such an optical device which can be driven even by small-sized and power-saving magnetic circuits and in which the insertion loss in the Faraday rotator may be reduced. The optical device comprises a Faraday rotator formed of a garnet single crystal, and a magnetic circuit applying an external magnetic field H that is smaller than the saturation magnetic field Hs of the Faraday rotator to the Faraday rotator.