Glass for use in dielectric optical waveguides

Abstract

Abstract 1507711 Sodium borosilicate glass POST OFFICE 14 July 1975 [29 July 1974 9 Dec 1974 24 Jan 1975] 33484/74 53097/74 and 3306/75 Heading C1M A sodium borosilicate glass has a composition comprising 95-99À99% by weight of a mixture of Na 2 O. B 2 O 3 and SiO 2 in a ratio lying within Region A of Figure 1, the glass also comprising 0À01-5% by weight of a redox buffering oxide (e.g. As 2 O 3 or Sb 2 O 3 ). The glass may be used to form the core and/or cladding of a dielectric optical waveguide, the waveguide preferably being made using a double crucible apparatus. In making the glass, the batch materials may be heated to 250‹C. in vacuo (to reduce the hydroxyl group content of the glass) and then melted, and then the melt held at 800-1400‹C. for ¢-2 hours while a dry reducing gas is bubbled therethrough (to achieve an optimum redox state). The reducing gas preferably consists of 80-100% (by volume) CO 2 and 0-20% CO. The melt is subsequently fired for up to 40 hours (e.g. in dry air, CO 2 or N 2 ). Specification 1.507,712 is referred to.

Inventors

No inventors recorded.

Bibliographic Details