Optical sensor having a wave guide substrate with interferometer integrated therein

US5262842A · kind A · utility

Assignee

• IOT Entwicklungsgesellschaft fur integrierte Optiktechnologie mbH · DE

Inventors

• Gunter Gauglitz · Tübingen, DE
• Jan Ingenhoff · Tübingen, DE
• Norbert Fabricius · Hockenheim, DE

Key dates

• Filing date: Oct 18, 1991
• Grant date: Nov 16, 1993
• Expiry date: Oct 18, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/7779
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor for detecting substances including hydrocarbons includes an integrated optical interferometer in the form of a Mach-Zehnder interferometer having a measuring arm and a comparison arm in a wave guide substrate. A polymer such as polysiloxane is applied as a superstrate to the wave guide in the region of the measuring arm. This superstrate can be penetrated by the substance to be detected. Swelling response, gas absorption, refractive index of the polymer and doping with chromophores or fluorophores, layer thickness and layer length are all parameters which can be adapted for a substance-selective performance. Other means of selection include various superstrates on a number of interferometers mounted parallel on a chip and polychrome measurements in combination with methods of pattern recognition constitute further means of selection.