Abstract: A light source apparatus according to an aspect of the present disclosure includes a light emitter, a wavelength conversion member, and an output section. The output section includes a first end section having a first surface facing the wavelength conversion member, a second end section located at the side opposite from the first end section, and second, third, fourth, and fifth surfaces in contact with the first and second end sections. The cross-sectional area of the output section taken along a plane perpendicular to the center axis gradually decreases from the first end section toward the second end section. The second, third, fourth, and fifth surfaces each incline with respect to the first surface. The inclination angle of each of the second, third, fourth, and fifth surfaces with respect to the first surface is greater than or equal to 40° but smaller than or equal to 58°.

Abstract: An illuminator includes a light source that outputs first light, a wavelength converter that converts the first light into second light, an optical element that reflects the first light toward the wavelength converter and transmits the second light, and an illumination system which is disposed on the opposite side of the optical element from the wavelength converter. The wavelength converter includes a substrate, a reflection layer facing a first surface of the substrate, a wavelength conversion layer having a second surface and facing the reflection layer, and a structural element facing the second surface and having a plurality of protrusions that reflect part of the first light. The plurality of protrusions each have an inclining surface that inclines with respect to the second surface, and at least part of the first light and reflected off the inclining surface enters the illumination system without traveling via the optical element.

Abstract: A light source apparatus according to an aspect of the present disclosure includes a light emitter that outputs first light, a wavelength conversion member that converts the first light into second light, an output section that outputs the second light, and a light collection member. The output section includes a first end section that faces the wavelength conversion member, a second end section that is located at the side opposite from the first end section along a center axis, and a tapering section that has a cross-sectional area that is perpendicular to the center axis and gradually decreases from the first end section toward the second end section, and the tapering section has a light output surface which inclines with respect to the center axis and via which the second light exits.

Abstract: A wavelength conversion element includes a substrate, reflection layer on the substrate, wavelength conversion layer in the reflection layer and converting a light in a first wavelength range into a light in a second wavelength range, structure in the wavelength conversion layer and scattering a part of the light in the first wavelength range, and optical layer in the structure, reflecting a part of the light in the first wavelength range, transmitting another part of the light in the first wavelength range, and transmitting the light in the second wavelength range. The structure includes a first structure portion, second structure portion, and planar portion between the first and second structure portions, the optical layers in the first and second structure portions have first reflectance for the light in the first wavelength range, and the optical layer in the planar portion has second reflectance.

Abstract: An illuminator includes a light source that outputs first light, a wavelength converter that converts the first light into second light, an optical element that reflects the first light toward the wavelength converter and transmits the second light, and an illumination system which is disposed on the opposite side of the optical element from the wavelength converter. The wavelength converter includes a substrate, a reflection layer facing a first surface of the substrate, a wavelength conversion layer having a second surface and facing the reflection layer, and a structural element facing the second surface and having a plurality of protrusions that reflect part of the first light. The plurality of protrusions each have an inclining surface that inclines with respect to the second surface, and at least part of the first light and reflected off the inclining surface enters the illumination system without traveling via the optical element.

Abstract: A wavelength conversion element according to the present disclosure includes a substrate, a reflecting layer, a wavelength conversion layer which is disposed on the reflecting layer, and which is configured to convert light in a first wavelength band into light in a second wavelength band, a structure which is disposed on the wavelength conversion layer, and which is configured to scatter the light in the first wavelength band, and an optical layer which is disposed on the structure, and which is configured to reflect a part of the light in the first wavelength band, transmit another part of the light in the first wavelength band, and transmit the light in the second wavelength band, wherein the optical layer is different in reflectance with respect to the light in the first wavelength band in accordance with an incidence angle of the light in the first wavelength band entering the optical layer.

Abstract: The wavelength conversion element according to the present disclosure includes a wavelength conversion layer which has a first surface and a second surface different from the first surface, and which includes a scattering element no higher than 5% in volume ratio, and which is configured to convert light in a first wavelength band into light in a second wavelength band different from the first wavelength band, and a plurality of protruding parts which is disposed so as to be opposed to the first surface, and which includes a first protruding part and a second protruding part adjacent to each other. A height of the plurality of protruding parts is no smaller than 1 ?m, and a distance between a vertex of the first protruding part and a vertex of the second protruding part in a direction along the first surface is no smaller than 3 ?m.

Abstract: The wavelength conversion element according to the present disclosure includes a wavelength conversion layer which has a first surface and a second surface different from the first surface, and which includes a scattering element no higher than 5% in volume ratio, and which is configured to convert light in a first wavelength band into light in a second wavelength band different from the first wavelength band, and a plurality of protruding parts which is disposed so as to be opposed to the first surface, and which includes a first protruding part and a second protruding part adjacent to each other. A height of the plurality of protruding parts is no smaller than 1 ?m, and a distance between a vertex of the first protruding part and a vertex of the second protruding part in a direction along the first surface is no smaller than 3 ?m.

Abstract: A wavelength conversion element according to the present disclosure includes a substrate, a reflecting layer, a wavelength conversion layer which is disposed on the reflecting layer, and which is configured to convert light in a first wavelength band into light in a second wavelength band, a structure which is disposed on the wavelength conversion layer, and which is configured to scatter the light in the first wavelength band, and an optical layer which is disposed on the structure, and which is configured to reflect a part of the light in the first wavelength band, transmit another part of the light in the first wavelength band, and transmit the light in the second wavelength band, wherein the optical layer is different in reflectance with respect to the light in the first wavelength band in accordance with an incidence angle of the light in the first wavelength band entering the optical layer.