Waveguide-Based Optical Chemical Sensors

Abstract
Chemical sensor based on Si3N4 waveguides, species-selective thin-films and Zeeman interferometry is demonstrated. Relative phase change between TE and TM modes is measured. Real-time and reversible response to toluene and other volatile organic compounds is achieved with ppm level sensitivity. A chemical sensor scheme based on selective sensing surfaces and highly sensitive integrated optical transduction methods. Using self-assembly techniques, species selective thin-films are covalently attached to the surface of Si3N4 channel waveguides to produce robust sensor elements. Exposure to targeted analytes results in the selective absorption of these molecules onto the waveguide surface causing a change in the effective refractive index of the guided modes. These relative changes in effective refractive index between TE and TM modes are precisely measured using Zeeman interferometry. Our measurements demonstrate reversible, real time sensing of volatile organic compounds at ppm levels. There is demonstrated a highly sensitibve chemical sensor scheme based on Si3N4 channel waveguides, species-selective surface coatings and Zeeman interferometry. The relative phase change between the TE and TM modes under exposure to chemical vapor is measured. The measurements demonstrate the real-time and reversible response with good sensitivity at low concentrations.

IP Status: Available both Exclusively and Non Exclusively

Reference Number: 331

S Number: DOE reference no.(s): 104,835; 89,677; 97,794

Patents & Applications:
United States National Patent Number 7190851 Issued on 03/13/2007 United States National Patent Number 6801677 Issued on 10/05/2004

Posted: 10-06-2004

Contact
John Mott
Technology Transfer Division
Los Alamos National Laboratory
P.O. Box 1663, MailStop C334
(505) 665-0883
jmott@lanl.gov

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Waveguide-Based Optical Chemical Sensors