Optical sensor for detection of chemical species

US5640234A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Christoph Roth · Bodenwerder, DE
• Yuan Liu · Kawagoe, JP
• Werner Prass · Mainz, DE
• Tetsu Yamamoto · Kawasaki, JP
• Kenji Motosugi · Kawagoe, JP

Key dates

• Filing date: Nov 7, 1995
• Grant date: Jun 17, 1997
• Expiry date: Nov 7, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/7776
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Disclosed and claimed is an optical sensor for the detection of chemical species. The optical sensor includes an optical waveguide having a guiding thin film. The thickness of the refrative index of the guiding thin film changes due to adsorption or absorption of the chemical species or reaction of the chemical species with the guiding thin film. The thickness of the guiding thin film is above the cutoff thickness in the presence of gaseous or liquid chemical species to be detected. And, the thickness of the guiding thin film is below the cutoff thickness in the absence of such chemical species.