A glass includes SiO.sub.2 in an amount of at least 60.0 wt.-% and an amount of WO.sub.3 from 0.1 ppm to 60.0 ppm. Tungsten is present in such oxidation states that a transmittance of the glass at a wavelength of 260 nm is at least 75.0%.

A glass includes SiO.sub.2 in an amount of at least 60.0 wt.-% and an amount of WO.sub.3 from 0.1 ppm to 60.0 ppm. Tungsten is present in such oxidation states that a transmittance of the glass at a wavelength of 260 nm is at least 75.0%.

A high temperature heater lamp including a ceramic envelope is disclosed. The ceramic envelope is substantially infrared transparent and is composed of a refractory ceramic. The heater lamp also includes two lead wires communicatively coupled via a filament. The filament is enclosed within the ceramic envelope, which is evacuated. The heater lamp may include at least two metallic IR shields within the ceramic envelope, at least one located on either side of the filament. The filament may be tungsten, a carbon filament, or molybdenum. At least one end of the ceramic envelope may be sealed with a metal cap affixed to the ceramic envelope by a high vacuum sealant. The heater lamp may be configured to operate at above 1500° C. The ceramic envelope may have a wall thickness less than 1 mm thick.

A high temperature heater lamp including a ceramic envelope is disclosed. The ceramic envelope is substantially infrared transparent and is composed of a refractory ceramic. The heater lamp also includes two lead wires communicatively coupled via a filament. The filament is enclosed within the ceramic envelope, which is evacuated. The heater lamp may include at least two metallic IR shields within the ceramic envelope, at least one located on either side of the filament. The filament may be tungsten, a carbon filament, or molybdenum. At least one end of the ceramic envelope may be sealed with a metal cap affixed to the ceramic envelope by a high vacuum sealant. The heater lamp may be configured to operate at above 1500° C. The ceramic envelope may have a wall thickness less than 1 mm thick.

A lamp has a light emitting element within a sealed transparent vessel. The vessel comprises a cylindrical section with a longitudinal axis L in parallel to a longitudinal axis F of the light emitting element. In order to provide a lamp suited for compact reflectors, a heat shielding element is arranged to shield at least infrared light. The heat shielding element is arranged in parallel to the longitudinal axis F of the light emitting element and has an axial extension of at least 80% of the light emitting element. The heat shielding element is arranged to shield infrared light emitted into directions perpendicular to the longitudinal axis F covering a circumferential extension of 20°-120° measured in cross section.

A lamp has a light emitting element within a sealed transparent vessel. The vessel comprises a cylindrical section with a longitudinal axis L in parallel to a longitudinal axis F of the light emitting element. In order to provide a lamp suited for compact reflectors, a heat shielding element is arranged to shield at least infrared light. The heat shielding element is arranged in parallel to the longitudinal axis F of the light emitting element and has an axial extension of at least 80% of the light emitting element. The heat shielding element is arranged to shield infrared light emitted into directions perpendicular to the longitudinal axis F covering a circumferential extension of 20°-120° measured in cross section.

Materials and optical components formed thereof that are suitable for use in a lighting apparatus to impart a color filtering effect to visible light. At least a portion of such an optical component is formed of a composite material comprising a polymeric matrix material and an inorganic particulate material that contributes a color filtering effect to visible light passing through the composite material, and the particulate material comprises a neodymium compound containing Nd.sup.3+ ions.

A high temperature heater lamp including a ceramic envelope is disclosed. The ceramic envelope is substantially infrared transparent and is composed of a refractory ceramic. The heater lamp also includes two lead wires communicatively coupled via a filament. The filament is enclosed within the ceramic envelope, which is evacuated. The heater lamp may include at least two metallic IR shields within the ceramic envelope, at least one located on either side of the filament. The filament may be tungsten, a carbon filament, or molybdenum. At least one end of the ceramic envelope may be sealed with a metal cap affixed to the ceramic envelope by a high vacuum sealant. The heater lamp may be configured to operate at above 1500° C. The ceramic envelope may have a wall thickness less than 1 mm thick.

A high temperature heater lamp including a ceramic envelope is disclosed. The ceramic envelope is substantially infrared transparent and is composed of a refractory ceramic. The heater lamp also includes two lead wires communicatively coupled via a filament. The filament is enclosed within the ceramic envelope, which is evacuated. The heater lamp may include at least two metallic IR shields within the ceramic envelope, at least one located on either side of the filament. The filament may be tungsten, a carbon filament, or molybdenum. At least one end of the ceramic envelope may be sealed with a metal cap affixed to the ceramic envelope by a high vacuum sealant. The heater lamp may be configured to operate at above 1500° C. The ceramic envelope may have a wall thickness less than 1 mm thick.

Embodiments of apparatus for providing radiant energy in the form of electromagnetic radiation are provided herein. In some embodiments a radiation source for electromagnetic radiation includes a tubular body formed from a material transparent to electromagnetic radiation; a filament disposed within the tubular body; and a reflective coating disposed on a portion of the tubular body to form a reflective portion, wherein the reflective portion is configured to minimize reflection of electromagnetic radiation emanating from the filament during use back to the filament.