A Scanning Near-Field Optical Microscope with Optical Distance Control

Abstract

An all optical scanning near-field microscope including vertical distance regulation is described. The probe-sample distance is maintained to within an accuracy of approximately lnm using a profilometer based on the principles of confocal microscopy. The profilometer is incorporated into a system where subwavelength resolution is obtained by scanning with an aperture in a metal-coated tapered optical fibre. The final system will be capable of producing both confocal and the higher resolution near-field images along with an accurate profile of the scanned surface using only optical techniques. Intensity maps of the near-zone fields produced from the cleaved face of an optical fibre are also p..