Optical intensity mapping on the nanometer scale by near-field photodetection optical microscopy.

Near-field photodetection optical microscopy (NPOM) is a fundamentally new approach to near-field optical microscopy. This scanning-probe technique uses a nanometer-scale photodiode detector as a near-field optical probe. We have fabricated probes for NPOM that have optically sensitive areas as small as 100 nm x 100 nm. These new NPOM probes have been employed to image light transmitted through holes in an aluminum film. Near-surface optical interference is observed near defects and edges of the aluminum film. The optical edge response is shown to be of the order of 100 nm.