Patent ID: 6215549
Filing Date: 2001-04-10
Classification: G01N

Abstract:
An optical characteristic measuring apparatus, for measuring an optical characteristic of a medium to be inspected, having a light source for applying a light beam to the medium and an input side optical system for focusing the light beam from the light source upon a specific interface of the medium, the light source and the input side optical system being disposed so that a portion of the light beam from the light source is applied to the specific interface at an angle less than a critical angle of total internal reflection at the specific interface and so that a portion of the light beam from the light source is applied to the specific interface at an angle greater than the critical angle of total internal reflection at the specific interface to produce evanescent light in the medium to measure an optical characteristic of the medium, said optical characteristic measuring apparatus comprising:an evanescent light beam light reception system disposed near the medium for receiving a light beam emitted in a direction different from an original propagation direction of the evanescent light produced in the medium when the light beam from the light source is applied to the medium, the received light beam being generated because of a portion of the evanescent light being deflected by optical heterogeneity of the medium.