The invention provides a high-refraction low-dispersion optical glass with refractive index of 1.76-1.80 and Abbe number of 47-51. The optical glass, comprising the following components by weight percentage: 0-3% of SiO.sub.2; 25-40% of B.sub.2O.sub.3; 20-40% of La.sub.2O.sub.3; 12-25% of Gd.sub.2O.sub.3; 6.5-15% of ZrO.sub.2; greater than 10% but less than or equal to 20% of ZnO; 0-5% of Ta.sub.2O.sub.5; 0-5% of Nb.sub.2O.sub.5; 0-10% of Li.sub.2O; less than 0.45 of (Ta.sub.2O.sub.5+Nb.sub.2O.sub.5)/(ZnO+Li.sub.2O); 0-10% of Y.sub.2O.sub.3; and below 625 C. of glass transition temperature Tg. With reasonable component ratio, the high-refraction low-dispersion optical glass favorable to precision molding with excellent transmittance can be easily enabled while realizing the required optical constant of the glass of the present invention.

A Faraday rotator includes a magnetic circuit including first to third magnetic materials each provided with a through hole through which light passes, and a Faraday element disposed in the through hole. When a direction where light passes through the through hole is defined as a direction of an optical axis, the first magnetic material is magnetized in a direction perpendicular to the direction of the optical axis, the second magnetic material is magnetized in a direction parallel to the direction of the optical axis, and the third magnetic material is magnetized in a direction perpendicular to the direction of the optical axis, and a length of the Faraday element along the direction of the optical axis is shorter than a length of the second magnetic material along the direction of the optical axis.

A Faraday rotator includes a magnetic circuit including first to third magnetic materials each provided with a through hole through which light passes, and a Faraday element disposed in the through hole. When a direction where light passes through the through hole is defined as a direction of an optical axis, the first magnetic material is magnetized in a direction perpendicular to the direction of the optical axis, the second magnetic material is magnetized in a direction parallel to the direction of the optical axis, and the third magnetic material is magnetized in a direction perpendicular to the direction of the optical axis, and a length of the Faraday element along the direction of the optical axis is shorter than a length of the second magnetic material along the direction of the optical axis.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

Provided is an optical glass which has optical properties including a high refractive index and high dispersibility, and can contribute to the correction of the influence of the change in temperature on image formation properties. The optical glass contains, in % by mass, a B.sub.2O.sub.3 component in an amount of more than 0% and equal to or less than 35.0%, a Ln.sub.2O.sub.3 component (wherein Ln represents at least one element selected from the group consisting of La, Gd, Y and Yb) in a total amount of 1.0 to 50.0% inclusive, and a BaO component in an amount of 10.0 to 50.0% inclusive, wherein the total mass of TiO.sub.2+ZrO.sub.2+WO.sub.3+Nb.sub.2O.sub.5+Ta.sub.2O.sub.5 is more than 0% and equal to or less than 50.0%. The optical glass has a refractive index of 1.75 or more and an Abbe's number of 18 to 42 inclusive, wherein the temperature coefficient (40 to 60 C.) of a relative refractive index (589.29 nm) falls within the range from +4.010.sup.6 to 10.010.sup.6 ( C..sup.1).

An optical boroaluminate glass article comprises: from greater than or equal to 10.0 mol % to less than or equal to 30.0 mol % Al.sub.2O.sub.3; from greater than or equal to 10.0 mol % to less than or equal to 55.0 mol % CaO; from greater than or equal to 10.0 mol % to less than or equal to 25.0 mol % B.sub.2O.sub.3; from greater than or equal to 0.0 mol % to less than or equal to 30.0 mol % SiO.sub.2; and from greater than or equal to 1.0 mol % to less than or equal to 20.0 mol % refractive index raising components. The optical boroaluminate glass article has a refractive index of the glass article, measured at 589.3 nm, of greater than or equal to 1.62, and a density of less than or equal to 4.00 g/cm.sup.3.

An optical boroaluminate glass article comprises: from greater than or equal to 10.0 mol % to less than or equal to 30.0 mol % Al.sub.2O.sub.3; from greater than or equal to 10.0 mol % to less than or equal to 55.0 mol % CaO; from greater than or equal to 10.0 mol % to less than or equal to 25.0 mol % B.sub.2O.sub.3; from greater than or equal to 0.0 mol % to less than or equal to 30.0 mol % SiO.sub.2; and from greater than or equal to 1.0 mol % to less than or equal to 20.0 mol % refractive index raising components. The optical boroaluminate glass article has a refractive index of the glass article, measured at 589.3 nm, of greater than or equal to 1.62, and a density of less than or equal to 4.00 g/cm.sup.3.

A solid state method of producing inorganic nanoparticles using glass is disclosed. The nanoparticles may not be formed until the glass is reacted with or degraded by contact with a fluid in vivo or in vitro.

A solid state method of producing inorganic nanoparticles using glass is disclosed. The nanoparticles may not be formed until the glass is reacted with or degraded by contact with a fluid in vivo or in vitro.