Toru OKAYAMA and Hidehiro SEKI¹

Aomori Industrial Research Center, 1-4-43 Kita-inter-kogyodanchi, Hachinohe-shi, Aomori 039-2245, Japan
¹Hachinohe Institute of Technology, 88-1 Ohbiraki, Myoh, Hachinohe-shi, Aomori 031-8501, Japan

(Received August 18, 2004; Accepted November 28, 2004)

A sensor probe with a microstructure, which is used for near-field scanning optical microscopes, plays an important role in the resolution and detection sensitivity of the microscope system. In this study, we devised a system for sharpening optical fibers, by which we could fabricate tapered tips of silica-based optical fibers reproducibly in a desired shape by controlling the solution temperature, etching time, and etching depth when applying chemical etching techniques using hydrofluoric acid. Furthermore, we evaluated the diameter of the core tip of an optical fiber by measuring the near-field pattern and comparing it with the Gaussian beam pattern of a non-edge-etched optical fiber. A strong correlation between the ratio of the 1/e²-value width of the beam profile of the near-field pattern to that of the Gaussian beam and the diameter of the extreme tip of the core became apparent.

Key words: optical fiber, probe, near-field optical microscope, near-field pattern, chemical etching, Gaussian beam