Optical gas detection using metal film enhanced leaky mode spectroscopy

Sensors based on fiber optics or optical waveguides are finding increasing interest for applications in aggressive environments, in the vicinity of high electric fields, or in areas where miniaturization is a necessity. Many of these optical sensors utilize interaction of evanescent fields with the environment. If the optical component is made of a polymer, the ability of polymers to ad- or absorb vapors can be utilized for the sensing of such vapors. This is based on changes in refractive indices or anisotropy upon interaction with the vapor.