A wavelength conversion device of the present disclosure includes a substrate, a phosphor layer that has a matrix containing zinc oxide and phosphor particles embedded in the matrix and that is supported by the substrate, a dielectric layer disposed between the substrate and the phosphor layer, and a protective layer that is disposed between the phosphor layer and the dielectric layer and that has an isoelectric point equal to or larger than 7. A main surface of the substrate includes, for example, first and second regions. The phosphor layer covers, for example, only the first region out of the first and second regions.

Apparatus, methods and systems are provided for improving the quality of illumination from a luminaire. The apparatus, methods and systems provide quantum dots, methods and apparatus for stimulating device light emission from quantum dots, sensors, and controllers to adjust quality of illumination from a luminaire.

Apparatus, methods and systems are provided for improving the quality of illumination from a luminaire. The apparatus, methods and systems provide quantum dots, methods and apparatus for stimulating device light emission from quantum dots, sensors, and controllers to adjust quality of illumination from a luminaire.

A phosphor wheel apparatus includes: a substrate made of a heat conductive material having a first light reflectance, the substrate having first and second surfaces facing each other; a phosphor layer disposed on the first surface of the substrate; an adhesive layer bonding the substrate and the phosphor layer to each other; and a plurality of fins disposed on the second surface of the substrate, wherein the adhesive layer includes an adhesive having first thermal conductivity and filler particles, and the filler particles have second thermal conductivity higher than the first thermal conductivity, and have a second light reflectance higher than the first light reflectance.

A wavelength conversion element includes: a wavelength conversion layer that is formed with a plurality of pores and that is excited by light in a first wavelength band to generate light in a second wavelength band different from the light in the first wavelength band; a first bonding layer formed at a first surface of the wavelength conversion layer; a second bonding layer bonded to the first bonding layer; and a reflection member that is formed at the second bonding layer and that reflects the light in the first wavelength band or the light in the second wavelength band. The first surface of the wavelength conversion layer is formed with a recess. A part of the first bonding layer is formed at the recess. The second bonding layer is formed to cover the recess. The first bonding layer and the second bonding layer are plasma polymerized films.

A light source device includes a semiconductor light-emitting element; an optical element including lens regions that change an intensity distribution of light emitted from the semiconductor light-emitting element; and a phosphor element that emits, as excitation light, the light with the intensity distribution changed by the optical element. Respective focal points of the lens regions are present in front of or behind a light-emitting surface of the phosphor element in different positions. At least one of the lens regions is astigmatic. An excitation beam from the at least one of the lens regions with the astigmatism forms a circle of least confusion near an associated one of the focal points, and a first focal line and a second focal line sandwiching the circle behind and in front of the circle, respectively. Beams from the lens regions overlap each other on the light-emitting surface of the phosphor element.

A wavelength conversion device according to an embodiment of the present disclosure includes a first base member, a second base member opposed to the first base member, and a phosphor layer with which a first space is filled. The second base member has a surface opposed to the first base member. The surface has an annular recessed portion. The recessed portion includes therein a plurality of protruding portions extending from an inner peripheral portion toward an outer peripheral portion. The first space is formed by the first base member and the recessed portion of the second base member.

Provided is a wavelength conversion member capable of improving brightness of a light source device. Wavelength conversion member according to the present disclosure includes: first phosphor layer that is disposed on an incidence side where excitation light enters, and contains a plurality of first phosphor particles; and second phosphor layer that is disposed on a side reverse to the incidence side and contains a plurality of second phosphor particles. First phosphor particles include an activation component, second phosphor particles include an activation component same as or different from the activation component included in first phosphor particles, and a concentration of the activation component in first phosphor layer is lower than a concentration of the activation component in second phosphor layer.

A light source system or apparatus configured with an infrared illumination source includes a gallium and nitrogen containing laser diode based white light source. The light source system includes a first pathway configured to direct directional electromagnetic radiation from the gallium and nitrogen containing laser diode to a first wavelength converter and to output a white light emission. In some embodiments infrared emitting laser diodes are included to generate the infrared illumination. In some embodiments infrared emitting wavelength converter members are included to generate the infrared illumination. In some embodiments a second wavelength converter is optically excited by a UV or blue emitting gallium and nitrogen containing laser diode, a laser diode operating in the long wavelength visible spectrum such as a green laser diode or a red laser diode, by a near infrared emitting laser diode, by the white light emission produced by the first wavelength converter, or by some combination thereof. A beam shaper may be configured to direct the white light emission and an infrared emission for illuminating a target of interest and transmitting a data signal. In some configurations, sensors and feedback loops are included.

A light source system or apparatus configured with an infrared illumination source includes a gallium and nitrogen containing laser diode based white light source. The light source system includes a first pathway configured to direct directional electromagnetic radiation from the gallium and nitrogen containing laser diode to a first wavelength converter and to output a white light emission. In some embodiments infrared emitting laser diodes are included to generate the infrared illumination. In some embodiments infrared emitting wavelength converter members are included to generate the infrared illumination. In some embodiments a second wavelength converter is optically excited by a UV or blue emitting gallium and nitrogen containing laser diode, a laser diode operating in the long wavelength visible spectrum such as a green laser diode or a red laser diode, by a near infrared emitting laser diode, by the white light emission produced by the first wavelength converter, or by some combination thereof. A beam shaper may be configured to direct the white light emission and an infrared emission for illuminating a target of interest and transmitting a data signal. In some configurations, sensors and feedback loops are included.