Abstract: A phosphor comprises a crystal phase with a chemical composition (Lu1-p-q, Cep, Mq)x?y?zO. M denotes one or more elements selected from the group consisting of Y, La, Sc, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. ? contains Si, which constitutes 90% or more by mole of ?. ? contains N, which constitutes 90% or more by mole of ?. The variables x, y, z, p, and q satisfy 5.5?x?6.5, 10.5?y?11.5, 19.5?z?20.5, 0<p<0.03, and 0?q?0.5.

Abstract: A light-emitting apparatus includes an excitation light source that emits first light; a light-emitting device on an optical path of the first light, the light-emitting device emitting second light having a wavelength in air; and a first converging lens on an optical path of the second light. The light-emitting device comprises: a photoluminescent layer that emits the second light by being excited by the first light; and a light-transmissive layer on the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a surface structure comprising projections or recesses arranged perpendicular to a thickness direction of the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction, the second light emitted from the light emitting surface. The surface structure limits the directional angle of the second light emittied from the light emitting surface.

Abstract: A phosphor includes a crystal phase with a chemical composition (LuxY1-x)yM3-y-zCez?p?q. M denotes one or more elements selected from the group consisting of La, Sc, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. ? contains Si, which constitutes 90% or more by mole of ?. ? contains N, which constitutes 90% or more by mole of ?. The variables x, y, z, p, and q satisfy 0<x?1, 1.5?y?3?z, 0<z?0.6, 5.5?p?6.5, and 10.5?q?11.5. The phosphor has an emission spectrum peak at a wavelength in the range of not less than 600 nm and not more than 680 nm.

Abstract: A phosphor contains a crystal phase having a chemical composition CexM3-x-y?6?11-z. M is one or more elements selected from the group consisting of Sc, Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. ? contains Si in an amount of 50 mol % or more of a total mol of ?. ? further contains Al. ? contains N in an amount of 80 mol % or more N of a total mol of ?. x satisfies 0<x?0.6. y satisfies 0?y?1.0. z satisfies 0?z?1.0.

Abstract: A phosphor contains a crystal phase having a chemical composition CexM3-x-y?6?11-z. M is one or more elements selected from the group consisting of Sc, Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. ? contains Si in an amount of 50 mol % or more of a total mol of ?. ?contains N in an amount of 80 mol % or more N of a total mol of ?. x satisfies 0<x?0.6. y satisfies 0?y?1.0. z satisfies 0?z?1.0. The phosphor shows a maximum peak of an emission spectrum in a wavelength range of 600 nm or more and 800 nm or less and a first peak of an excitation spectrum in a wavelength range of 500 nm or more and 600 nm or less.

Abstract: A light-emitting apparatus includes; a light-emitting device including a photoluminescent layer that receives excitation light and emits light including first light having a wavelength ?a in air, and a light-transmissive layer located on or near the photoluminescent layer; and an optical fiber that receives the light from the photoluminescent layer at one end of the optical fiber and emits the received light from the other end thereof. A surface structure is defined on at least one of the photoluminescent layer and the light-transmissive layer, and the surface structure has projections or recesses or both and limits a directional angle of the first light having the wavelength ?a in air.

Abstract: An optical scanning device includes: a first waveguide that propagates light by total reflection; and a second waveguide. The second waveguide includes: a first multilayer reflective film; a second multilayer reflective film that faces the first multilayer reflective film; and a first optical waveguide layer directly connected to the first waveguide and located between the first and second multilayer reflective films. The first optical waveguide layer has a variable thickness and/or a variable refractive index and propagates the light transmitted through the first waveguide. The first multilayer reflective film has a higher light transmittance than the second multilayer reflective film and allows part of the light propagating through the first optical waveguide layer to be emitted to the outside. By changing the thickness of the first optical waveguide layer and/or its refractive index, the direction of the part of the light emitted from the second waveguide is changed.

Abstract: An optical scanning device includes a waveguide array including a plurality of waveguides arranged in a first direction. Each waveguide includes: an optical waveguide layer that propagates light supplied to the waveguide in a second direction intersecting the first direction; a first mirror having a first reflecting surface intersecting a third direction; and a second mirror having a second reflecting surface that faces the first reflecting surface. The optical waveguide layer is located between the first and second mirrors and has a variable thickness and/or a variable refractive index for the light. The width of the first mirror and the width of the second mirror are each larger than the width of the optical waveguide layer. The first mirror has a higher light transmittance than the second mirror and allows part of the light propagating through the optical waveguide layer to be emitted in the third direction.

Abstract: A phosphor comprises a crystal phase that has a chemical composition of (Y1-x-y,Cex,Lay)?Si?-zAlzN?O, where the ? satisfies 5.5???6.5, the ? satisfies 9.5???12.5, the ? satisfies 17.5???22.5, the x satisfies 0<x?0.1, the y satisfies 0?y?0.4, and the z satisfies 0?z?0.5. A light emission spectrum of the phosphor includes a peak within a wavelength range of not less than 600 nm and not more than 660 nm.

Abstract: A projector includes a light source unit, a spatial light modulator configured to control light from the light source unit for each pixel to form an optical image, and a projection optical system configured to project the optical image formed by the spatial light modulator onto a target. The light source unit includes a solid-state light source and a wavelength convertor. The solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive. The wavelength convertor contains a red phosphor including Ce as a luminescent center that is configured to emit second light upon receiving the green light. The second light has a spectrum with a peak wavelength of 600 to 700 nm, inclusive. The red phosphor contains a nitride or an oxynitride as a host material.

Abstract: A fiber light source includes a solid-state light source, a wavelength convertor, and an optical fiber. The solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive. The wavelength convertor is disposed on the light output side or the light incident side of the optical fiber and contains a red phosphor. The red phosphor includes Ce as a luminescent center, and is excited by at least part of the green light to emit second light. The second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive. The red phosphor contains a nitride or an oxynitride as a host material.

Abstract: A light-emitting apparatus includes: a solid-state light source; and a wavelength convertor. The solid-state light source emits first light including green light with a peak wavelength in a range of 480 to 550 nm, inclusive. The wavelength convertor contains a red phosphor including Ce as a luminescent center. The red phosphor is excited by at least part of the green light to emit second light. The second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive. The red phosphor contains a nitride or an oxynitride as a host material.

Abstract: A flocculation monitoring apparatus and a flocculation monitoring method are provided, and the flocculation monitoring apparatus and the flocculation monitoring method are capable of stably measuring a flocculation state of water to be treated even when the number (density) of flocs has increased. A measurement-light applying part (laser-light applying part 10) applies a measurement light to a measurement region (18) in the water to be treated (8) and a scattered-light receiving part (12) receives a scattered light due to particles of the water to be treated. A measurement value arithmetic part (arithmetic circuit 48) calculates an index related to flocculation of the water to be treated, by using an amplitude of a light reception signal acquired in the scattered-light receiving part.

Abstract: The phosphor according to an aspect of the present disclosure contains a crystal phase having a chemical composition CexYyLa3-x-ySi6N11, where x and y satisfy 0<x?0.6, and (1.5?x)?y?(3?x). The phosphor has an emission spectral peak within a wavelength range of 600 nm or more and 660 nm or less and a first excitation spectral peak within a wavelength range of 480 nm or more and 550 nm or less.

Abstract: A phosphor contains a crystal phase having a chemical composition CexM3-x-y?6?11-z. M is one or more elements selected from the group consisting of Sc, Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. ? contains Si in an amount of 50 mol % or more of a total mol of ?. ?contains N in an amount of 80 mol % or more N of a total mol of ?. x satisfies 0<x?0.6. y satisfies 0?y?1.0. z satisfies 0?z?1.0. The phosphor shows a maximum peak of an emission spectrum in a wavelength range of 600 nm or more and 800 nm or less and a first peak of an excitation spectrum in a wavelength range of 500 nm or more and 600 nm or less.

Abstract: A lamp includes: first and second semiconductor light-emitting elements adapted to emit excitation light; a wavelength conversion element adapted to convert the excitation light into light having a peak wavelength different from that of the excitation light; and a concave mirror adapted to reflect the excitation light emitted from the semiconductor light-emitting elements to the wavelength conversion element and reflect the light from the wavelength conversion element toward an outside of the lamp. A distance y1 from an optical axis of the first semiconductor light-emitting element to an optical axis of the concave mirror satisfies (D+Dphos)/2?y1?4f, and a distance y2 from an optical axis of the second semiconductor light-emitting element to the optical axis of the concave mirror satisfies 4f<y2?R.

Abstract: An ultraviolet light emitting device includes: a first substrate; a second substrate; a gas in a space between the first substrate and the second substrate; electrodes directly or indirectly on a first main surface of the first substrate; a dielectric layer that is located in a first region directly or indirectly on the first main surface of the first substrate and covers the electrodes, the dielectric layer being not located in a second region directly or indirectly on the first main surface of the first substrate, the second region being different from the first region, the first region including regions in which the electrodes are located; and a light-emitting layer that is located in the second region and/or located directly or indirectly on at least one of second and third main surfaces of the second substrate and emits the ultraviolet light in the gas due to electrical discharge between the electrodes.

Abstract: An ultraviolet light emitting device comprises: a first substrate having a main surface; a second substrate facing the main surface of the first substrate; a gas in a space between the first substrate and the second substrate; electrodes directly or indirectly on the main surface of the first substrate; a dielectric layer that is located directly or indirectly on the main surface of the first substrate and covers the electrodes; and a first light-emitting layer. The first light-emitting layer is located directly or indirectly on the dielectric layer and emits ultraviolet light in the gas due to electrical discharge between the electrodes. The first light-emitting layer is thicker in first regions on the dielectric layer than in second regions. The second regions include at least part of regions directly above the electrodes.

Abstract: An ultraviolet irradiation apparatus includes: a first substrate; a second substrate; electrodes disposed directly or indirectly on the first substrate; a dielectric layer covering the electrodes; a sealant joining together the first and second substrates; a light-emitting layer that is disposed directly or indirectly on the dielectric layer and/or a surface of the second substrate; and a reaction vessel disposed directly or indirectly on a surface of the second substrate. The reaction vessel includes a tubular structure, an inlet channel and an outlet channel. The tubular structure has a ratio ha/hc of 5 to 10, where ha is a diameter of a circle inscribed in an inner bottom surface of the tubular structure, and hc is an inner height of the tubular structure.

Abstract: A light-emitting apparatus includes an excitation light source that emits first light; a light-emitting device on an optical path of the first light, the light-emitting device emitting second light having a wavelength in air; and a first converging lens on an optical path of the second light. The light-emitting device comprises: a photoluminescent layer that emits the second light by being excited by the first light; and a light-transmissive layer on the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a surface structure comprising projections or recesses arranged perpendicular to a thickness direction of the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction, the second light emitted from the light emitting surface. The surface structure limits the directional angle of the second light emittied from the light emitting surface.