Apertureless near-field optical microscopy with differential and close-proximity detection

A new method of apertureless near-field optical microscopy that combines laterally differential detection with close-proximity detection has been developed. The laterally differential detection allows the light scattered from the probe apex to be distinguished from the background light. The close-proximity detection is done using a microfabricated photosensitive cantilever; it is thought to be a form of heterodyne detection, which provides a high signal level. This method makes it possible to detect the light scattered from the probe apex, which depends on the coupling between the probe apex dipole and the sample feature dipole.