CaO in Optical Waveguides

Optical waveguides have been formed by using femtosecond laser pulses in ZnO-P2O5 glasses. This system is useful for optical applications such as waveguides, but is not chemically durable. It is believed that the addition of alkaline-earth oxides will add chemical durability to the system while maintaining the waveguide forming properties. In this project, CaO is considered as a potential additive to the ZnO-P2O5 glass system. To facilitate the selection of a glass composition for waveguides a glass forming ternary diagram consisting of CaO-ZnO-P2O5 was created. Glass compositions for the diagram were melted twice for a total of three hours. Properties such as glass transition temperature (T9) and density were recorded for each composition. Glasses with partial crystallization or phase separation were recorded separately from pure glass. The bottom limit for glass forming capability is near the 30% P2O5 line. The density of a glass decreases with increasing CaO content