Patent ID: 6577396
Filing Date: 2003-06-10
Classification: G01N

Abstract:
A surface plasmon sensor comprisinga dielectric block, a metal film which is formed on one face of the dielectric block and is brought into contact with a sample, a light source emitting a light beam, an optical system which causes the light beam to enter the dielectric block and converges the light beam on the interface of the dielectric block and the metal film so that components of the light beam impinge upon the interface at various angles of incidence including angles of total reflection, a photodetector means which consists of an array of a plurality of photodetector elements extending in a predetermined direction and is positioned so that each of the components of the light beam reflected at the interface in total reflection at various angles are received by the respective photodetector elements in one-to-one correspondence, and so that each photodetector element measures surface plasmon resonance and outputs a light detecting signal, a comparator means which compares the light detecting signals output from each of the photodetector elements with respect to the direction of the array of the photodetector elements, and an operation means which determines the reflecting angle at which the intensity of the light reflected at the interface takes a minimum value on the basis of the result of comparison of the light detecting signals.