Microfabrication of near-field optical probes

Near-field optical microscopy generally uses a tapered optical fiber, which is metal coated, to form a sub-wavelength sized light source. Here, a technique for the fabrication of a new type of probe is described. The new design is based on atomic force microscope probes and consists of a silicon nitride cantilever with a solid transparent conical tip. The probes are made using micromechanical techniques, which allow batch fabrication of the probes. A near-field scanning optical microscope system was built to test the probes. This system features force detection by a beam deflection technique and subsequent force feedback together with a conventional optical microscope. A major advantage of the apparatus is the ease at which images are obtained. Results on a test sample show that an optical resolution of 300 nm can be obtained together with a simultaneous height image. (C) 1996 American Vacuum Society.