Detection of volatile organic compounds with functionalized long-period gratings and micro-ring resonators

Long-period gratings (LPGs) and micro-photonic SOI ring-resonators were coated with materials derived from polydimethyl-siloxane to detect volatile organic compounds in air. Both sensors are capable of detecting the refractive index change of the polymer upon uptake of the analyte. The LPGs response was further amplified by fiber cavity ring-down.