摘要 |
PROBLEM TO BE SOLVED: To provide a borate glass, which, even in the case of irradiation with a light of a wavelength of 350 to 450 nm, is suppressed in the reduction of light transmittance in this wavelength range, and a lens using this borate glass. SOLUTION: The borate glass is made to contain one or more kinds of rare earth elements. As the rare earth elements, it is preferable to select lanthanum, preferably as a lanthanum oxide. This glass can be used for the lens. COPYRIGHT: (C)2005,JPO&NCIPI
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