A UV emitting device having at least one first phosphor that absorbs UV radiation of a wavelength shorter than 200 nm and at least one second phosphor which absorbs UV radiation of a wavelength between 220 nm and 245 nm. The at least one first phosphor emits UV radiation of a wavelength between 220 nm and 245 nm and the at least one second phosphor emits UV radiation of a wavelength between 250 nm and 315 nm. The at least one first phosphor and the at least one second phosphor are disposed in the form of layers, wherein the at least one first phosphor layer is positioned between a discharge volume and the at least one second phosphor layer.

A UV steriliser assembly and associated method for disinfection purposes. The assembly includes a reflector (16) and a UV source, e.g. a lamp (10), configured to emit ultraviolet light at a range of wavelengths. Dependent on the assembly configuration, the reflector (16) is configured to permit or inhibit transmission therethrough of particular UV wavelengths known to assist in the photo-repair of micro-organisms. Transmission of wavelengths known to be destructive to micro-organisms can also be targeted. In this way the effectiveness of the assembly for sterilisation purposes can be optimised.

An autonomous, permanently illuminating object includes a sheath that defines an interior space in which is disposed a glass capsule containing a gaseous tritium light source. The sheath defines a transparent region. A layer of photoluminescent pigments is disposed between the glass capsule and the transparent region of the sheath.

An autonomous, permanently illuminating object includes a sheath that defines an interior space in which is disposed a glass capsule containing a gaseous tritium light source. The sheath defines a transparent region. A layer of photoluminescent pigments is disposed between the glass capsule and the transparent region of the sheath.

The invention relates to a luminescent converter (10, 12) for a phosphor-enhanced light source (100, 102, 104). The luminescent converter comprises a first luminescent material (20) configured for absorbing at least a part of excitation light (hv0) emitted by a light emitter (40, 42) of the phosphor-enhanced light source, and for converting at least a part of the absorbed excitation light into first emission light (hv1) comprising a longer wavelength compared to the excitation light. The luminescent converter further comprising a second luminescent material (30) comprising organic luminescent material (30) and configured for absorbing at least a part of the first emission light emitted by the first luminescent material, and for converting at least a part of the absorbed first emission light into second emission light (hv2) having a longer wavelength compared to the first emission light. An effect of the luminescent converter according to the invention is that the two-step light conversion according to the invention generates a relatively small Stokes shift of the light emitted by the organic luminescent material. The inventors have found that by reducing the Stokes shift of the organic luminescent material, the width of the spectrum of the second emission light is limited to reduce an infrared part in the emission spectrum. As such, the efficiency is improved.

The techniques described herein relate to systems, apparatus, articles of manufacture, and methods for light generation. An example apparatus for ultraviolet (UV) radiation generation includes a microwave cavity comprising an electrodeless UV bulb, the electrodeless UV bulb comprising a bulb fill capable of emitting UV light, a synthesizer configured to generate a microwave signal, and a solid-state amplifier configured to amplify the microwave signal to generate an amplified microwave signal for igniting the bulb fill to emit UV light.

The techniques described herein relate to systems, apparatus, articles of manufacture, and methods for light generation. An example apparatus for ultraviolet (UV) radiation generation includes a microwave cavity comprising an electrodeless UV bulb, the electrodeless UV bulb comprising a bulb fill capable of emitting UV light, a synthesizer configured to generate a microwave signal, and a solid-state amplifier configured to amplify the microwave signal to generate an amplified microwave signal for igniting the bulb fill to emit UV light.