Scanning probe optical microscopy of evanescent fields

Abstract

Two new methods for probing evanescent fields using a Dimension™ 3000 atomic force microscope (AFM) from Digital Instruments are described. The first method uses a fiber-optic pickup probe to collect light generated by a commercial silicon AFM probe, which perturbs the evanescent field. The pickup probe is mounted directly onto the AFM cantilever probe holder so that it tracks with the AFM probe tip as it scans a sample but is positioned in such a manner as to permit the use of conventional laser deflection distance regulation. The second method uses a novel bent optical fiber probe with a chemically etched conical quartz tip to perturb the evanescent field together with a metallized cladding to collect the scattered light.