Embodiments of the invention include a light source and a wavelength converting structure disposed in a path of light emitted by the light source. The wavelength converting structure includes a first phosphor that emits infrared light and a second phosphor that emits visible light. In some embodiments, the light source emits first light, the second phosphor absorbs the first light and emits second light, and the first phosphor absorbs the first light and emits third light and absorbs the second light and emits fourth light.

An article comprising a luminescent nanoparticle is described, wherein the luminescent nanoparticle is selected from the group consisting of oxide nanoparticles, aluminate nanoparticles, and germanate nanoparticles; and wherein the luminescent nanoparticle is doped with one or more metals or rare-earth elements. A method of making a luminescent nanoparticle is also described, the method comprising the steps of: providing a nanoparticle, wherein the nanoparticle is doped with one or more chemical elements, and heating the nanoparticle to a temperature of between about 1000 C. and about 1200 C. to alter the crystal structure of the nanoparticle and/or to create oxygen vacancies in the nanoparticle. A persistent luminescent nanoparticle is described, said persistent luminescent nanoparticle being selected from the group consisting of: LaAlO.sub.3 nanoparticles, Gd.sub.2O.sub.3 nanoparticles, SrAl.sub.2O.sub.4 nanoparticles, Y.sub.2O.sub.3 nanoparticles, and combinations thereof; wherein the nanoparticle is doped with about 1 mol % or less of a chemical element selected from the group consisting of: holmium, europium, ytterbium, neodymium, magnesium, and combinations thereof.

Lutetium oxide-based scintillator materials, as well as corresponding methods and systems, are described.

[Objective] To provide a ceramic emitter that exhibits high radiation intensity and excellent wavelength selectivity. [Solution] A ceramic emitter includes a polycrystalline body that has a garnet structure represented by a compositional formula R.sub.3Al.sub.5O.sub.12 (R: rare-earth element) or R.sub.3Ga.sub.5O.sub.12 (R: rare-earth element) and has pores with a porosity of 20-40%. The pores have a portion where the pores are connected to one another but not linearly continuous, inside the polycrystalline body.

A light source device includes an excitation light source, and a fluorescence layer configured to emit fluorescence by receiving excitation light emitted from the excitation tight source. The fluorescence layer includes at least one selected from a group consisting of a first fluorescent substance and a second fluorescent substance. The first fluorescent substance is configured to emit fluorescence having a peak wavelength ranging :from 400 nm to 510 nm, inclusive, by receiving the excitation light. The second fluorescent substance is configured to emit fluorescence having a peak wavelength ranging from 580 nm to 700 nm, inclusive, by receiving the excitation light. The first fluorescent substance and the second fluorescent substance each have a fluorescence lifetime ranging from 0.1 nanoseconds to 250 nanoseconds, inclusive. Energy density of the excitation light is 10 W/mm.sup.2 or more.

A fluorescence emitting module includes: a fluorescent substrate consisting essentially of a sintered fluorescent substance that includes a fluorescent material; and a rotator that rotates the fluorescent substrate about an axis extending in a thickness direction of the fluorescent substrate.

A polymerizable composition includes at least one monomer, a photoinitiator capable of initiating polymerization of the monomer when exposed to light, and a phosphor capable of producing light when exposed to radiation (typically X-rays). The material is particularly suitable for bonding components at ambient temperature in situations where the bond joint is not accessible to an external light source. An associated method includes: placing a polymerizable adhesive composition, including a photoinitiator and energy converting material, such as a down-converting phosphor, in contact with at least two components to be bonded to form an assembly; and, irradiating the assembly with radiation at a first wavelength, capable of conversion (down-conversion by the phosphor) to a second wavelength capable of activating the photoinitiator, to prepare items such as inkjet cartridges, wafer-to-wafer assemblies, semiconductors, integrated circuits, and the like.

The present invention includes: a radiation detecting unit including a fluorescent body expressed by the formula ATaO.sub.4: B, C (in the formula, A is selected from at least one kind of element from among rare-earth elements involving 4f-4f transitions, B is selected from at least one kind of element, different from A, from among rare-earth elements involving 4f-4f transitions, and C is selected from at least one kind of element from among rare-earth elements involving 5d-4f transitions); an optical fiber that transmits photons generated by the fluorescent body; a light detector that converts the photons transmitted via the optical fiber 3 one by one into electrical pulse signals; a counter that counts the number of electrical pulse signals converted by the light detector; an analysis and display device 6 that obtains a radiation dose rate on the basis of the number of electrical pulse signals counted by the counter.

An article comprising a luminescent nanoparticle is described, wherein the luminescent nanoparticle is selected from the group consisting of oxide nanoparticles, aluminate nanoparticles, and germanate nanoparticles; and wherein the luminescent nanoparticle is doped with one or more metals or rare-earth elements. A method of making a luminescent nanoparticle is also described, the method comprising the steps of: providing a nanoparticle, doping the nanoparticle with one or more chemical elements, heating the nanoparticle to a temperature of between about 1000? C. and about 1200? C. to alter the crystal structure of the nanoparticle and/or to create oxygen vacancies in the nanoparticle. A persistent luminescent nanoparticle is described, said persistent luminescent nanoparticle being selected from the group consisting of: LaAlO.sub.3 nanoparticles, Gd.sub.2O.sub.3 nanoparticles, SrAl.sub.2O.sub.4 nanoparticles, Y.sub.2O.sub.3 nanoparticles, and combinations thereof; wherein the nanoparticle is doped with about 1% or less of a chemical element selected from the group consisting of: holmium, europium, ytterbium, neodymium, magnesium, and combinations thereof.

Provided is a wavelength converter including a phosphor ceramic containing a first phosphor that emits fluorescence due to a parity-forbidden transition, and a phosphor part containing a second phosphor that emits fluorescence due to a parity-allowed transition. A main surface of the phosphor ceramic has a concave and convex structure including a plurality of convex parts and a plurality of concave parts. The phosphor part is arranged inside the plurality of concave parts in the phosphor ceramic. Also provided is a light emitting device including the wavelength converter, and a solid-state light source that emits light with which the wavelength converter is irradiated and which has a light emission peak within a wavelength range of 400 nm or more and less than 500 nm.