Polydimethylsiloxane coated optical fiber sensor for detection of organic volatile compounds

A compact optical fiber sensor coated with polydimethylsiloxane for detection of organic volatile compounds (e.g. toluene) has been developed and tested. The sensor consists of two mirrors (two optical fiber ends) facing to each other and a variable length cavity. One fiber used as an input/output fiber, and the other one, used as a reflector are aligned using a PDMS coating and together form Fabry-Perot interferometer. We investigated toluene impact on the spectral characteristic of reflected light power in time. Using FFT we determine the period of interference pattern of measured characteristic depending on the time. We also detect that the change in temperature within range from 20°C to 50°C does not affect the period of interference pattern.