An improved method for producing fiber tips for scanning near-field optical microscopy is presented. The improvement consists of chemically etching quartz optical fibers through their acrylate jacket. This new method is compared with the previous one in which bare fibers were etched. With the new process the meniscus formed by the acid along the fiber does not move during etching, leading to a much smoother surface of the tip cone. Subsequent metallization is thus improved, resulting in better coverage of the tip with an aluminum opaque layer. Our results show that leakage can be avoided along the cone, and light transmission through the tip is spatially limited to an optical aperture of a 100-nm dimension.
© 1998 Optical Society of America
(050.1220) Diffraction and gratings : Apertures
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(180.5810) Microscopy : Scanning microscopy
(240.6700) Optics at surfaces : Surfaces
(350.5730) Other areas of optics : Resolution
Patrick Lambelet, Abdeljalil Sayah, Michael Pfeffer, Claude Philipona, and Fabienne Marquis-Weible, "Chemically Etched Fiber Tips for Near-Field Optical Microscopy: A Process for Smoother Tips," Appl. Opt. 37, 7289-7292 (1998)