High reflectivity Bragg reflectors based on gold nanoparticle/Teflon-like composite material as a new approach to the organic solvent detection

We report on the properties of a new optical sensing element for organic solvents based on polymeric distributed Bragg reflector (DBR), which can be easily interfaced with optical fibers. The DBR is a periodic stack of alternating Teflon-like and gold nanoparticle/Teflon-like composite layers showing high reflectivity in the optical telecommunication spectral range and sensing proper-ties due to the peculiar absorbing properties of the composite layers. The swelling of the composite layers in presence of organic vapors causes a DBR periodicity change and this results in the shift of the high reflectivity window.