High-strength glass-ceramic ferrule for SC-type single-mode optical fiber connector

A high-strength Li/sub 2/O-Al/sub 2/O/sub 3/-SiO/sub 2/ glass-ceramic ferrule has been realized by using a precise glass-ceramic drawing technique which was developed to reduce production costs. With the ion-exchange process that applies the residual compressive stress to the surface layer, the bending strength of the ferrule reached about 500 MPa, which is similar to that of an alumina ferrule. It maintained a bending strength of 310 MPa after scratching. The Young's modulus and micro Vickers hardness are similar to those of silica-glass optical fiber. The linear expansion coefficient is far smaller than that of zirconia. These characteristics suggest the stable physical contact and the easy endface polishing as the optical connector.