Abstract: [Problem] To provide a light-emitting device which does not undergo the deterioration in luminous efficiency associated with the long-term use. [Solution] A light-emitting device (1) comprises a light-emitting element (10) which can emit blue light and a phosphor (2) which is composed of a single kind of single crystal and can emit yellow light upon the irradiation with the light emitted from the light-emitting element (10) which serves as excitation light. Thus, it becomes possible to prevent the deterioration in luminous efficiency associated with the deterioration in a binder or the like compared with a light-emitting device which utilizes multiple kinds of granular phosphors, because any binder for binding phosphors to each other is not required in the light-emitting device (1).

Abstract: The present invention provides a single crystal for an optical isolator having a Faraday rotation angle exceeding that of TGG single crystal in a wavelength region of 1064 nm or longer or in a wavelength region of shorter than 1064 nm, and is capable of realizing enlargement of crystal size, a production process thereof, an optical isolator, and an optical processor that uses the optical isolator. The single crystal according to the present invention is composed of a terbium aluminum garnet single crystal, and mainly a portion of the aluminum is replaced with lutetium.

Abstract: The present invention provides a garnet single crystal comprising a terbium aluminum garnet single crystal, wherein a portion of the aluminum is substituted with scandium, and a portion of at least one of the aluminum and terbium is substituted with at least one type selected from the group consisting of thulium, ytterbium and yttrium.

Abstract: The present invention is a garnet-type single crystal represented by the following general formula: (Tb3-xScx)(Sc2-yAly)Al3O12-z??(1) (wherein, x satisfies 0<x<0.1).

Abstract: [Problem] To provide a light-emitting device which does not undergo the deterioration in luminous efficiency associated with the long-term use. [Solution] A light-emitting device (1) comprises a light-emitting element (10) which can emit blue light and a phosphor (2) which is composed of a single kind of single crystal and can emit yellow light upon the irradiation with the light emitted from the light-emitting element (10) which serves as excitation light. Thus, it becomes possible to prevent the deterioration in luminous efficiency associated with the deterioration in a binder or the like compared with a light-emitting device which utilizes multiple kinds of granular phosphors, because any binder for binding phosphors to each other is not required in the light-emitting device (1).

Abstract: A wavelength conversion element 20 has a periodic polarization reversal structure formed in a non-linear optical crystal, wherein positive/negative polarity is periodically alternated in period d expressed by the following formula (1), outputs light having frequency of 2? from the incident light having frequency of ?, and is characterized in that the non-linear optical crystal is a nitride single crystal: d=m?/[2(n2??n?)]??(1) where, m represents the order of phase matching, ? represents the wavelength of the incident light, n? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of ?, and n2? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of 2?.

Abstract: The present invention provides a garnet single crystal comprising a terbium aluminum garnet single crystal, wherein a portion of the aluminum is substituted with scandium, and a portion of at least one of the aluminum and terbium is substituted with at least one type selected from the group consisting of thulium, ytterbium and yttrium.

Abstract: The present invention provides a single crystal for an optical isolator having a Faraday rotation angle exceeding that of TGG single crystal in a wavelength region of 1064 nm or longer or in a wavelength region of shorter than 1064 nm, and is capable of realizing enlargement of crystal size, a production process thereof, an optical isolator, and an optical processor that uses the optical isolator. The single crystal according to the present invention is composed of a terbium aluminum garnet single crystal, and mainly a portion of the aluminum is replaced with lutetium.

Abstract: A wavelength conversion element 20 has a periodic polarization reversal structure formed in a non-linear optical crystal, wherein positive/negative polarity is periodically alternated in period d expressed by the following formula (1), outputs light having frequency of 2? from the incident light having frequency of ?, and is characterized in that the non-linear optical crystal is a nitride single crystal: d=m?/[2(n2??n?)]??(1) where, m represents the order of phase matching, ? represents the wavelength of the incident light, n? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of ?, and n2? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of 2?.