Wet chemical etching technique for optical fibers

摘要

A wet chemical etching technique is disclosed for forming a lensed optical fiber (20). In particular, the fiber is placed in a mixture comprising buffered hydrofluoric acid (e.g., HF and NH4F) and a treating agent comprising acetic acid or citric acid. The relative concentrations of the constituents are adjusted so that a double conical lens (22, 24) 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%.