LAUSR

A compact fiber-optic Fabry-Perot interferometric (FFPI) volatile organic compounds (VOCs) sensor is fabricated based on a single mode fiber (SMF) and a polymethyl methacrylate (PMMA) film. The VOCs induce the swelling effect and refractive index changes of PMMA film. The swelling of PMMA film affects the cavity length of Fabry-Perot interferometer resulting in shift of resonant dip, while the change in refractive index influences reflection resulting in change of extinction ratio (ER). The sensitivities of 2.7 pm/ppm for ethanol and 2.17 pm/ppm for acetone are achieved. Moreover, this sensor is insensitive to the inorganic gases. In addition, it has the advantages of ease of fabrication and high sensitivity to VOCs.