Glass for wavelength division multiplexing optical filter

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 MgO, 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 K₂O, and 0-3 wt % 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 % 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.