A light source is provided that includes a laser operable to emit laser light at a wavelength in a range from 460 nanometers to 470 nanometers and a converter assembly arranged so as to absorb the laser light emitted by the laser and to emit photoluminescent light produced by the laser light and having a longer wavelength than the laser light. The converter assembly has a converter element with a ceramic doped with Eu.sup.3+ such that under irradiation of the laser light the converter assembly emits photoluminescent light in the red spectral range.

A light source is provided that includes a laser operable to emit laser light at a wavelength in a range from 460 nanometers to 470 nanometers and a converter assembly arranged so as to absorb the laser light emitted by the laser and to emit photoluminescent light produced by the laser light and having a longer wavelength than the laser light. The converter assembly has a converter element with a ceramic doped with Eu.sup.3+ such that under irradiation of the laser light the converter assembly emits photoluminescent light in the red spectral range.

A process for ultrasensitive in vitro detection and/or quantification of a substance of interest in a sample is performed by detecting the luminescence emission by photoluminescent inorganic nanoparticles. The process includes (i) use of photoluminescent particles comprising a photoluminescent inorganic nanoparticle consisting of a crystalline matrix having at least 10.sup.3 rare-earth ions, and coupled to a targeting agent for the substance to be analyzed, under conditions conducive to their association with the sample substance to be analyzed; (ii) exciting the rare-earth ions of the particles by an illumination device having a power of at least 50 mW and an excitation intensity of at least 1 W/cm.sup.2; (iii) detecting the luminescence emission by the particles after single-photon absorption; and (iv) determining the presence and/or concentration of the substance by interpreting said luminescence measurement. This process can be used for in vitro diagnostic purposes and as an in vitro diagnostic kit.

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 concerns a luminescent particle comprising a nanoparticle of formula

A.sub.1xLn.sub.xVO.sub.4(1y)(PO.sub.4).sub.y (I)

in which A is selected from yttrium (Y), gadolinium (Gd), lanthanum (La), and mixtures thereof; Ln is selected from europium (Eu), dysprosium (Dy), samarium (Sm), neodymium (Nd), erbium (Er), ytterbium (Yb), and mixtures thereof; 0<x<1; and 0<y<1; characterized in that the nanoparticle on its surface has tetraalkylammonium cations in an amount such that said nanoparticle has a zeta potential, , of less than or equal to 28 mV in an aqueous medium with a pH5, more particularly with a pH5.5, and with an ionic conductivity >100 S.cm.sup.1.

It also concerns a method for preparing such luminescent particles, a colloidal suspension of these particles, and the use thereof as a diagnostic agent, and also a diagnostic kit comprising such luminescent particles.

A new concept of bi-luminescent security pigments includes lanthanide doped rare-earth compound with rare-earth free compound and its ink formulation. The unique features of this bi-luminescent security ink is that it emits two different colors when it is illuminated by using two different excitation wavelengths. This important feature makes it most suitable for printing of security codes or QR codes/security images on currency, important official documents, food and medicinal packaging etc. The prospective use of this bi-luminescent security ink provides a ground-breaking opening for easily printable, highly stable and unclonable bi-luminescent security codes for anti-counterfeiting applications.

A high-energy LED is provided, in particular based on the n-polar technique, comprising a Eu.sup.3+ activated converter material based on tungsten/molybdenum oxide. Surprisingly, these materials do not show any saturation.

The present disclosure relates to a phosphor ceramic comprising a plurality of luminescence conversion materials, wherein a luminescence conversion material serves as a matrix material for the others.

The present application concerns multimodal composite products for imaging, in particular for diagnostic imaging, and optionally for therapy, in particular composite products which are capable of being used as contrast agents, in particular in magnetic resonance imaging (MRI), and/or in imaging techniques such as, for example, in optical imaging, in the optical detection of oxidants, in positron emission tomography (PET), in tomodensitometry (TDM) and/or in ultrasound imaging, and optionally simultaneously for use in therapy. These products are based on a particle comprising or consisting of a portion provided with a contrast agent activity and/or a paramagnetic activity, and a portion provided with a luminescent activity and optionally an oxidant detection activity.

The invention relates to a polymer film comprising an inorganic fluorescent compound and an organic fluorescent compound. The invention further relates methods for preparing such a film, and to its use as wavelength conversion film in a solar cell.