Computer-controlled technique for cutting curved grooves in polished fiber-optic coupler substrates

The fabrication of polished fiber-optic couplers requires a substrate or glass block to protect the fiber during grinding and polishing steps. Polished coupler substrates are a major source of process and performance variability, due to mechanical variation of the block and groove. An automated system capable of cutting repeatable grooves in glass blocks has been developed, which greatly improves the quality of the substrates. The fiber groove longitudinal profile (which determines interaction length) and other parameters can be defined and controlled programmatically with this approach. The transverse groove profile exhibits a flat, smooth bottom and minimal width, which allows for flatter polishing of fiber/substrate assemblies.<>