Patent ID: 6277330
Filing Date: 2001-08-21
Classification: G01N

Abstract:
An optical sensor for directly detecting a chemical substance dissolved or dispersed in water comprising:at least one sensing element, at least one light source unit and a first light detector,the sensing element including an optically transparent substrate and a polymer thin film capable of interacting with said chemical substance dissolved or dispersed in water and formed on said substrate and arranged in contact with said water, and whereinthe light source unit is positioned on the substrate side of said sensing element,the first light detector is positioned on the substrate side of said sensing element, andsaid substrate couples light from said light source unit to said polymer thin film at a predetermined angle, and functions as light coupling means for coupling light reflected by said sensing element to said first light detector, and said predetermined incident angle is set at a value smaller than a critical angle of total internal reflection on the interface between said polymer thin film and said water and close to said critical angle.