Patent ID: 6046448
Filing Date: 2000-04-04
Classification: G01N,G01Q,Y10S

Abstract:
A scanning near field optical microscope based on the use of polarized light wherein the interval between the tip of a probe and the surface of a sample or a medium to be measured is kept so small as to be within an action distance where an inter-atomic force or other interactive forces result between the tip and the surface, a beam is scanned over the surface through a means allowing a two-dimensional scanning, the beam is radiated onto a tiny area of the surface or the beam emanating from a tiny area of the surface is detected, and therewith the form of sample and two-dimensional optical information thereof are simultaneously obtained, comprising:a light source;a probe with a sharpened tip;a means to maintain the interval between the tip and the surface within an action distance where an inter-atomic force or other interactive forces result between the tip and the surface;a means to obtain a polarized beam carrying the optical information of a tiny area of sample or medium, by allowing a beam from the light source to interact with the surface at the tip;a light receiving means to receive the polarized beam;a modulating means which is placed on the light path between the light source and light receiving means and gives a periodically changing optical delay to the beam; anda rectifying means to selectively separate, out of the output from the light receiving means, wave components having frequencies integer times as high as the modulation frequency worked by the modulating means.