Wet chemical etching technique for optical fibers

Abstract

A wet chemical etching technique is disclosed for forming a lensed optical fiber. In particular, the fiber is placed in a mixture comprising buffered hydrofluoric acid (e.g., HF and NH4 F) and a treating agent comprising acetic acid or citric acid. The relative concentrations of the constituents are adjusted so that a double conical lens is formed which requires no further operations (such as fire polishing) to provide coupling efficiencies of about 80% with a standard deviation of less than ±2%.Published versio