A NEW SPHERICAL MIRROR-FINISH SURFACE MACHINING TECHNOLOGY FOR OPTICAL-FIBER CONNECTOR

This paper describes a new grinding technology for the fabrication of spherical mirror-finish endfaces on PC (Physical Contact) optical fiber connectors to be used in optical fiber communications systems. The convex spherical endface is obtained by rotating and pushing the connector perpendicularly against the concave surface of a metal bond micro-grain grinding wheel. A truing wheel is used to maintain precise grinding wheel concavity, and electrolytic dressing of the grinding wheel allows a mirror-finish surface (0.06 mu m R(max)) to be produced directly, without the conventional need for lapping. The endface is subsequently fine-polished with similar conditions to that employed after conventional fabrication. Experiments were performed to determine the appropriate conditions for achieving desired surface smoothness and spherical shape accuracy. PC connectors produced demonstrated sufficiently high optical light transmission characteristics of the average return loss of 47 dB.