摘要 |
The invention relates to first, second and third glasses for wavelength division multiplexing optical filters. The first glass contains 50-65 wt% of SiO2, 5-25 wt% of Na2O, 4-20 wt% of K2O, 0-20 wt% of CaO, 0-10 wt% of Mg O, 0-10 wt% of BaO, 0-10 wt% of Al2O3, and 0-10 wt% of TiO2. The second glass contains 35-55 wt% of SiO2, 10-30 wt% of TiO2, 4-20 wt% of ZrO2, 5-25 wt% of Na2O, 0-10 wt% of Al2O3, 0-20 wt% of CeO2, 0-5 wt% of Li2O, 0-20 wt% of K2 O, and 0-3wt% of at least one metal oxide selected from MgO, CaO, SrO, BaO, and ZnO. The third glass contains 35-55 wt% of SiO2, 0-20 wt.degree./ of Al2O3, 0-10 wt% of B2O3, 1-35 wt% of TiO2, 1-15 wt% of CeO2, 0-10 wt% of Li2O, 5-25 wt% of Na2O, and 0-20 wt% of K2O.
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