Alcohols detection by a polymeric sensing film deposited on a long-period fiber grating

In this paper, we report the construction and characterization of a sensor to detect volatile organic compounds, particularly alcohols. The was fabricated by depositing polydimethylsiloxane sensing film on surface long-period fiber grating (LPFG). LPFG spectrum, which taken as response, measured in Teflon chamber, where different concentrations methanol, ethanol, propanol, butanol samples were injected. Spectral shifts lower wavelength observed for last three samples. However, shift higher wavelengths case methanol observed, attributed fact that its refractive index is smaller than one PDMS. Therefore, curves response function concentration performed using analysis techniques: fixed wavelength, spectrum amplitude spectral trough principal components (PCA) method. results showed regular behavior responses according molecular weight A discussion use each technique performed.