An image detector for a radiation-based imaging technique is disclosed. The image detector may comprise a detector material on a substrate. The detector material may be an optically active material represented by the following formula (I) (M′).sub.8 (M″M′″).sub.6O.sub.24(X,X′).sub.2:M″″ Further is disclosed the use of the image detector and the use of the optically active material represented by the formula (I).

The present invention provides a red light emitting glass ceramic and a preparation method thereof, and an LED/LD light emitting device. A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ cordierite of the red light emitting glass ceramic capable of realizing blue light excited red light emission is a crystal phase material, wherein A is at least one of Mg, Ca, Sr, Ba and Zn and at least comprises Mg. The present invention particularly provides the red light emitting glass ceramic taking a chemical formula A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ as a crystal phase. The present invention further provides a preparation method of the transparent glass ceramic. The glass ceramic comprising the crystal phase, with the chemical formula of Mg.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+, is excited by blue light to emit red light, the internal/external quantum efficiencies reaching up to 94.5%/70.6%, respectively.

A lighting device for adjusting the color temperature of white light emitted by a luminescent material is disclosed. The lighting device comprises: a luminescent material configured to emit white light when being exposed to electromagnetic radiation of a preselected wavelength range; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a first wavelength range selected from the range of 230-330 nm; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a second wavelength range, different from the first wavelength range, selected from the range of 300-600 nm; a metering unit configured to adjust the ratio of the irradiances of electromagnetic radiation of first wavelength range and of electromagnetic radiation of second wavelength range that is exposed on the luminescent material.

A lighting device for adjusting the color temperature of white light emitted by a luminescent material is disclosed. The lighting device comprises: a luminescent material configured to emit white light when being exposed to electromagnetic radiation of a preselected wavelength range; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a first wavelength range selected from the range of 230-330 nm; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a second wavelength range, different from the first wavelength range, selected from the range of 300-600 nm; a metering unit configured to adjust the ratio of the irradiances of electromagnetic radiation of first wavelength range and of electromagnetic radiation of second wavelength range that is exposed on the luminescent material.

A fluorescent member includes: a wavelength converter including an incidence part on which a light of a light source is incident and an output part from which a converted light subjected to wavelength conversion as a result of excitation by an incident light is output; and a reflecting part provided in at least a portion of a surface of the wavelength converter. The wavelength converter is comprised of a material whereby a degree of scattering of the light of the light source incident via the incidence part and traveling toward the output part is smaller than in the case of a polycrystalline material.

The invention relates to a material represented by the following formula (I)
(M′).sub.8(M″M′″).sub.6O.sub.24(X,X′).sub.2:M″″   formula (I).
Further, the invention relates to a luminescent material, and to different medical imaging and diagnostic methods of using the material. Also disclosed is a method of securely identifying an item using the material.

A phosphor includes silica particles as a base material, Eu, Al, and an alkaline earth metal that is Ca or Mg. The phosphor contains 0.01 mol to 15 mol of the Eu in terms of metal element with respect to 100 mol of the silica particles, 0.5 mol to 25 mol of the Al in terms of metal element with respect to 100 mol of the silica particles, and 0.1 mol to 2.0 mol of the alkaline earth metal in terms of metal element with respect to 100 mol of the silica particles.

A material represented by the following formula (I)
(M).sub.8M.sub.6M.sub.6O.sub.24(X,S).sub.2:Mformula (I).
Also disclosed is an ultraviolet radiation sensing material, an X-radiation sensing material, a device and a method for determining the intensity of ultraviolet radiation.

The invention relates to a material represented by the following formula (I)

(M).sub.8(MM).sub.6O.sub.24(X, X).sub.2:M

formula (I).
Further, the invention relates to a luminescent material, and to different medical imaging and diagnostic methods of using the material. Also disclosed is a method of securely identifying an item using the material.

The invention relates to a material represented by the following formula (I)
(M).sub.8(MM).sub.6O.sub.24(X,X).sub.2:Mformula (I). Further, the invention relates to a luminescent material, to different uses, and to a device.