Abstract: A phosphor has a phosphor body including a phosphor phase formed of A3B5O12:Ce having a garnet structure, a matrix phase having a refractive index higher than a refractive index of the phosphor phase, and a crystal phase formed of YAlO3 having a perovskite structure. A content of the crystal phase is more than 0 vol % and is equal to or less than 7.0 vol % in a volume ratio with respect to the phosphor body. A is at least one selected from a group including Lu, Gd, Tb, Ga, and Y, and B is Al.

Abstract: A phosphor includes a phosphor body including a phosphor phase formed of A3B5O12:Ce having a garnet structure, a matrix phase having a refractive index higher than a refractive index of the phosphor phase, and an oxide layer provided between the phosphor phase and the matrix phase. The oxide layer includes a composite oxide of a metal contained in the phosphor phase and a metal contained in the sintering additive. A content of the oxide layer is equal to or more than 0.1 vol % and is equal to or less than 0.9 vol % in a volume ratio with respect to the phosphor body. A is at least one selected from a group including Lu, Gd, Tb, Ga, and Y, and B is Al.

Abstract: A phosphor includes a phosphor phase made of A3B5O12:Ce having a garnet structure; and a matrix phase having a refractive index higher than a refractive index of the phosphor phase. A content of the phosphor phase is 56 vol % or more and 70 vol % or less in terms of a volume ratio with respect to a total including the matrix phase and the phosphor phase. A is at least one selected from the group consisting of Lu, Gd, Tb, Ga, and Y. B is Al.

Abstract: A light source apparatus according to an aspect of the present disclosure includes a first light source that outputs a first luminous flux, a second light source that outputs a second luminous flux, a combiner, a width adjuster that reduces the difference in width between the first luminous flux and the second luminous flux, a first light collection system, a first diffuser, a second light collection system, and a homogenizing system. The first luminous flux traveling via the width adjuster, the combiner, and the first light collection system is collected at a first position, and the second luminous flux traveling via the combiner and the first light collection system is collected at a second position. The width adjuster and the first light collection system approach the aspect ratio and size of a first image formed by the first luminous flux to those of a second image formed by the second luminous flux.

Abstract: A wavelength conversion element according to the present disclosure includes: a wavelength conversion layer; a first substrate; a second substrate; a first intermediate layer; and a second intermediate layer. A linear expansion coefficient of the first substrate is smaller than a linear expansion coefficient of the wavelength conversion layer. The linear expansion coefficient of the wavelength conversion layer is smaller than a linear expansion coefficient of the second substrate. The linear expansion coefficient of the first substrate is smaller than the linear expansion coefficient of the second substrate. A thermal conductivity of the first substrate is larger than a thermal conductivity of the wavelength conversion layer. A thermal conductivity of the second substrate is larger than the thermal conductivity of the wavelength conversion layer.

Abstract: A wavelength conversion element according to the present disclosure includes: a wavelength conversion layer; a first substrate; a second substrate; a first intermediate layer; and a second intermediate layer. A linear expansion coefficient of the first substrate is smaller than a linear expansion coefficient of the wavelength conversion layer. The linear expansion coefficient of the wavelength conversion layer is smaller than a linear expansion coefficient of the second substrate. The linear expansion coefficient of the first substrate is smaller than the linear expansion coefficient of the second substrate. A thermal conductivity of the first substrate is larger than a thermal conductivity of the wavelength conversion layer. A thermal conductivity of the second substrate is larger than the thermal conductivity of the wavelength conversion layer.