A SIMPLE TECHNIQUE FOR THE MANUFACTURE OF OPTICAL PROBES FOR SCANNINGNEAR-FIELD OPTICAL MICROSCOPES

Scanning near-field optical microscopy (SNOM) is a new technique which can resolve objects with sub-wavelength resolution. A convenient tech nique is to use a sharp fibre tip which detects an evanescent light fi eld, the intensity of which depends exponentially on distance. The sha rp tip is made by heating and stretching an optical fibre to draw it o ut into a fine tip, and subsequently etching the tip in hydrofluoric a cid to reduce its radius of curvature to about 100 nm. Features as sma ll as 5 nm in height and less than 100 nm in width have been observed with the fibre mounted in a novel head adapted for use with Digital In struments Nanoscope II.