Provided is optical glass containing, in terms of mol % of cations: 10 to 60% of a La.sup.3+ component; more than 0% and up to 75% of a Ga.sup.3+ component; and 5 to 75% of a Nb.sup.5+ component, in which a total amount of the La.sup.3+ component, Ga.sup.3+ component, and Nb.sup.5+ component is 60 to 100%.

Optical glass filters are provided that include a filter glass showing an optimized transmission spectrum which has a high transmission in the wave length range of 300 to 400 nm and a very low transmission in the visible wave length range. The glass has an especially high optical quality and is excellently suitable as an optical filter for generating UV light without a proportion of visible light. The optical glass filters include the components nickel oxide and cobalt oxide.

An optical glass includes, in terms of mol % of cations, a total amount of La.sup.3+, Y.sup.3+, and Gd.sup.3+ components falling within a range of from 5% to 65% and a total amount of Zr.sup.4+, Hf.sup.4+, and Ta.sup.5+ components failing within a range of from 5% to 65%, and a relationship expressed in Expression (1) given below is satisfied. (La.sup.3++Y.sup.3++Gd.sup.3+)×(Zr.sup.4+ Hf.sup.4++Ta.sup.3+)≥400(%).sup.2.

A glass article is composed of a glass having a demixing factor in respect of its hydrolytic resistance in a range from 0.10 to 1.65.

A glass has a transmittance at a wavelength of 220 nm of at least 30% and a transmittance at a wavelength of 200 nm of less than 4.0%, the glass having a total platinum content of less than 3.5 ppm. A device and a sterilizer include a light source configured to output ultraviolet light and a lamp cover covering the light source and including the glass.

Provided is optical glass containing, in terms of mol % of cations: 10 to 60% of a La.sup.3+ component; more than 0% and up to 75% of a Ga.sup.3+ component; and 5 to 75% of a Nb.sup.5+ component, in which a total amount of the La.sup.3+ component, Ga.sup.3+ component, and Nb.sup.5+ component is 60 to 100%.

Provided is a silica glass member for hermetic sealing of an ultraviolet SMD LED element to be suitably used for hermetic sealing of, and as a transmission window material for, a surface mount-type package (SMD) having an ultraviolet LED mounted thereon and configured to emit ultraviolet light in a wavelength range of from 200 nm to 350 nm. The silica glass member for hermetic sealing includes a silica glass substrate, which is homogeneously and integrally formed without an internal boundary, wherein the silica glass substrate has: a first surface on an inside opposed to an SMD LED element; and a second surface on an outside corresponding to the first surface, wherein an outer peripheral portion of the first surface has formed therein a substrate joining plain surface for joining to the container outer periphery joining plain surface, and wherein the second surface on the outside corresponding to the first surface has formed therein a lens-like convex portion configured to process emitted light from the ultraviolet SMD LED element.

The present disclosure relates to glass articles, a method of making the glass articles, and uses of the glass articles. The glass article has a UV-transmittance of more than 90% at 350 nm and at 500 nm and a total amount of Si.sub.2, B.sub.2O.sub.3 and Al.sub.2O.sub.3 of at least 75 mol %. The article is preferably used in the fields of biotechnology, MEMS, CIS, MEMS-like pressure sensor, display, micro array, electronic devices, microfluidics, semiconductor, high precision equipment, camera imaging, display technologies, sensor/semicon, electronic devices, home appliance, diagnostic product, and/or medical device.

Glass compositions include phosphorus oxide (P.sub.2O.sub.5), niobia (Nb.sub.2O.sub.5), barium oxide (BaO) and potassium oxide (K.sub.2O) as essential components and may optionally include titania (TiO.sub.2), calcium oxide (CaO), sodium oxide (Na.sub.2O), lithium oxide (Li.sub.2O), bismuth oxide (Bi.sub.2O.sub.3), strontium oxide (SrO), tungsten oxide (WO.sub.3) and other components. The glasses may be characterized by high refractive index at 587.56 nm at comparably low density at room temperature.

Glass compositions include phosphorus oxide (P.sub.2O.sub.5), niobia (Nb.sub.2O.sub.5), barium oxide (BaO) and potassium oxide (K.sub.2O) as essential components and may optionally include titania (TiO.sub.2), calcium oxide (CaO), sodium oxide (Na.sub.2O), lithium oxide (Li.sub.2O), bismuth oxide (Bi.sub.2O.sub.3), strontium oxide (SrO), tungsten oxide (WO.sub.3) and other components. The glasses may be characterized by high refractive index at 587.56 nm at comparably low density at room temperature.