A luminescent material is disclosed with emission in the near infrared wavelength range, the luminescent material including Sc.sub.1-x-yA.sub.yRE:Cr.sub.x, wherein MO=P.sub.3O.sub.9, BP.sub.3O.sub.12, SiP.sub.3O.sub.12; A=Lu, In, Yb, Tm, Y, Ga, Al, where 0x0.75, 0y0.9. A wavelength converting structure including the luminescent phosphor is also disclosed.

Examples of a monolithic phosphor composite for measuring a parameter of an object are disclosed. The composite comprises a thermographic phosphor and a metal oxide material that are dried and calcinated at high temperatures to form a ceramic metal oxide phosphor composite. The ceramic metal oxide phosphor composite is used in an optical device for measuring the parameter of the measuring object. The device comprises a fiber optic probe with a light guide, a light source operatively coupled to the fiber optic probe to provide excitation light into the light guide, a monolithic ceramic metal oxide phosphor composite functionally coupled to a tip of the fiber optic probe, a sensor operatively coupled to the fiber optic probe to detect the emitted light and a processing unit functionally coupled to the sensor to process the emitted light. When the monolithic ceramic metal oxide phosphor composite is illuminated with the excitation light it emits light in a wavelength different from the excitation light and a change in emission intensity at a single wavelength or the change in intensity ratio of two or more wavelengths, a shift in emission wavelength peak or a decay time of the phosphor luminescence is a function of the measuring parameter.

A lighting apparatus including at least one light emitting diode (LED) chip configured to emit blue light; a green phosphor having a light emission peak in a range of 500 nm to 550 nm; and a red phosphor having a light emission peak in a range of 600 nm to 650 nm, in which the red phosphor includes a first red phosphor having a light emission peak in a range of 620 nm to 630 nm and a second red phosphor having a light emission peak in a range of 630 nm to 640 nm, and the full widths at half maximum of the first and second red phosphors are in a range of 20 nm to 60 nm, respectively.

The invention relates to a method for the preparation of a lithium silicate glass or a lithium silicate glass ceramic which comprise cerium ions and are suitable in particular for the preparation of dental restorations, the fluorescence properties of which largely correspond to those of natural teeth. The invention also relates to a lithium silicate glass and a lithium silicate glass ceramic which can be obtained using the method according to the invention, the use thereof as dental material and in particular for the preparation of dental restorations, as well as a glass-forming composition which is suitable for use in the method according to the invention.

An optical storage phosphor, a method for checking an authenticity feature, and an apparatus for carrying out a method, relate to an authenticity feature and to a value document. An inorganic optical storage phosphor is provided having a garnet structure and predetermined composition.

The present invention generally relates to a field emission light source and specifically to a field emission light source adapted to emit ultraviolet (UV) light. The light source has a UV emission member provided with an electron-excitable UV emitting material. The material is at least one of LuPO.sub.3:Pr.sup.3+, Lu.sub.2Si.sub.2O.sub.2:Pr.sup.3+, LaPO.sub.4:Pr.sup.3+, YBO.sub.3:Pr.sup.3+ and YPO.sub.4:Bi.sup.3+.

A phosphor of a chemically stable inorganic luminescent material having a NASICON structure and an application product including the phosphor, such as a light-emitting device. A phosphor having the formula of A.sub.1+xB.sub.xC.sub.2xD.sub.3X.sub.12:AE.sub.y where A is one or two types of elements of monovalent metal cations, B is one or two types of elements of trivalent cations, C is one or two types of elements of tetravalent cations, D is one or two types of elements of pentavalent cations, X is one or two types of elements of N, O, F, P, S, O, Cl, and Br, AE is one or two types of elements of Mn, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Th, U, and Bi, 0x2, and 0y0.1.

The invention relates to a converter system, for instance for a light emitting device, comprising: a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.

The invention relates to a converter system, for instance for a light emitting device, comprising: a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.

The present invention generally relates to a system for treating a fluid and specifically to a treatment system configured for improved bacterial reduction, wherein the system comprises a field emission based UV light source adapted to emit light within a ultraviolet C (UVC) spectrum with a wavelength range having an upper range limit being higher compared to light emitted from a mercury based UV light source.