In an embodiment an illumination system includes an illumination source that emits a primary electromagnetic radiation having a spectrum of wavelengths and an energy conversion layer that converts at least a portion of the primary electromagnetic radiation to a secondary electromagnetic radiation having a different spectrum of wavelengths than the primary electromagnetic radiation. The energy conversion layer may have a viewing surface, a bottom surface opposed to the viewing surface, and an edge surface normal to the viewing surface and the bottom surface. The primary electromagnetic radiation may be incident on the edge surface of the energy conversion layer.

An optoelectronic semiconductor light source includes a semiconductor chip configured to emit primary radiation, a Bragg mirror, and a luminescence conversion element configured to convert at least part of the primary radiation into secondary radiation having a longer wavelength, wherein the Bragg mirror is arranged between the semiconductor chip and the luminescence conversion element, the Bragg mirror is reflective for the secondary radiation and transmissive for the primary radiation, the Bragg mirror includes reflector layers of at least three different materials with different refractive indices, the Bragg mirror includes at least two different kinds of layer pairs, each kind of layer pairs being made up of reflective layers of two different materials, and the different kinds of layer pairs having different Brewster angles for p-polarized radiation.

An optoelectronic semiconductor light source includes a semiconductor chip configured to emit primary radiation, a Bragg mirror, and a luminescence conversion element configured to convert at least part of the primary radiation into secondary radiation having a longer wavelength, wherein the Bragg mirror is arranged between the semiconductor chip and the luminescence conversion element, the Bragg mirror is reflective for the secondary radiation and transmissive for the primary radiation, the Bragg mirror includes reflector layers of at least three different materials with different refractive indices, the Bragg mirror includes at least two different kinds of layer pairs, each kind of layer pairs being made up of reflective layers of two different materials, and the different kinds of layer pairs having different Brewster angles for p-polarized radiation.

A floodlight device comprises a light-emitting element that emits laser light, a fluorescent element on which light emitted from the light-emitting element is incident and which converts at least a portion of said light into fluorescent light that is output therefrom, a first optical system on which light output from the fluorescent element is incident, and a second optical system on which light exiting the first optical system is incident and which causes said light to be made into a collimated light beam that is made to exit therefrom so as to be directed toward the exterior of the device, a divergence angle of light incident on the second optical system is greater than a divergence angle of light incident on the first optical system.

A floodlight device comprises a light-emitting element that emits laser light, a fluorescent element on which light emitted from the light-emitting element is incident and which converts at least a portion of said light into fluorescent light that is output therefrom, a first optical system on which light output from the fluorescent element is incident, and a second optical system on which light exiting the first optical system is incident and which causes said light to be made into a collimated light beam that is made to exit therefrom so as to be directed toward the exterior of the device, a divergence angle of light incident on the second optical system is greater than a divergence angle of light incident on the first optical system.

A light source unit according to an embodiment of the present disclosure includes: a light source section; and a wavelength conversion element that is excited by exciting light from the light source section to emit fluorescent light. The wavelength conversion element includes a substrate that is rotatable around a rotation axis, a phosphor layer including a plurality of phosphor particles, and a quantum-dot layer including a plurality of quantum dots. The phosphor layer and the quantum-dot layer are disposed in this order relative to the light source section.

A light source unit according to an embodiment of the present disclosure includes: a light source section; and a wavelength conversion element that is excited by exciting light from the light source section to emit fluorescent light. The wavelength conversion element includes a substrate that is rotatable around a rotation axis, a phosphor layer including a plurality of phosphor particles, and a quantum-dot layer including a plurality of quantum dots. The phosphor layer and the quantum-dot layer are disposed in this order relative to the light source section.

Provided are a light emitting element capable of maintaining high fluorescent intensity over a long period, and a fluorescent light source device. The light emitting element according to the present invention includes: a substrate; a reflection layer formed of a material containing Ag or Al, formed on the upper layer of the substrate; a diffusion prevention layer formed of a layer at least part of which being crystallized, the diffusion prevention layer being formed in contact with a surface of the reflection layer on a side opposite to the substrate; an enhanced reflection layer formed in contact with a surface of the diffusion prevention layer on a side opposite to the substrate; and a fluorescent body layer formed on the upper layer of the enhanced reflection layer.

The present invention has as its object the provision of a fluorescent light source device capable of stably obtaining high luminous efficiency and a production process of the same. The fluorescent light source device of the present invention includes a fluorescent plate which has a fluorescent light-emitting layer formed of a polycrystalline material and in which a periodic structure body is formed on an excitation light incident side of the fluorescent light-emitting layer. The fluorescent plate has a thermal diffusion layer which is directly bonded to a front surface of the fluorescent light-emitting layer on the excitation light incident side and has a thermal conductivity larger than that of the fluorescent light-emitting layer, and a high thermal conductive layer provided on a back surface of the fluorescent light-emitting layer opposite to the excitation light incident side. The high thermal conductive layer is formed of a light reflection layer and a bonding layer made of a metal, and the fluorescent plate is provided so as to cover a part of a surface of a heat dissipation substrate disposed on a side of the high thermal conductive layer side.

Provided is a partial drive-type light source device including an excitation light source that is formed from a plurality of light-emitting elements and is partially drivable, a phosphor sheet disposed at a position separated from the excitation light source and containing a phosphor that converts at least part of a wavelength region of incident light from the excitation light source and releases emitted light in a wavelength region differing from the incident light, and a wavelength-selective reflection film that is disposed between the excitation light source and the phosphor sheet and that transmits at least part of light in the wavelength region of the incident light from the excitation light source and reflects at least part of light in the wavelength region of the emitted light from the phosphor sheet.