Patent ID: 6949732
Filing Date: 2005-09-27
Classification: B82Y,G01Q

Abstract:
1. An optical apparatus comprising: a light source; a metal member disposed on a planar substrate so as to have at least one pointed part with a width which monotonically decreases in a first direction and delimiting a gap in an area where no metal member is disposed, and where no pointed part exists in a second direction which is orthogonal to the first direction; a polarization modulator which switches a direction of polarization of light from the light source between orthogonal directions in which one of the directions is parallel to the first direction and an other direction which is parallel to the second direction; an optical member for irradiating the gap and the pointed part with light from the light source through the polarization modulator; a detector for detecting at least one of light having passed through an object and light which is at least one of reflected and scattered by the object; and a separator for removing a signal caused by background light and for extracting only a signal of near-field light from the signal outputted from the detector by using synchronous signal detection with switching of polarization direction by the polarization modulator.