SPR fibre sensor sensitised by fluoroxiloxane polymers

h simple SPR optical fibre sensor working with a monochromatic light source and based on resonance in a stabilised silver film is presented here. It c an be used either as an optical fibre refractometer, in the range of refrac tive index: 1.355-1.405 with a sensitivity of 4.5 x 10(-5), or as a chemica l vapour sensor. For the detection of vapours of chlorinated hydrocarbon co mpounds and of aromatic compounds, the sensitive part of the fibre is coate d with fluorosiloxane polymers. Detection limits of 3000 ppm were obtained for trichloroethylene and of 180 ppm for xylene. The sensitivities of detec tion of the optical fibre sensor coated with fluorosiloxane polymers are di scussed. For the chlorinated hydrocarbon compounds, the difference between the refractive indices of the solvent and the polymer is the predominant fa ctor. For aromatic compounds whose boiling temperature is higher, the conde nsation effect in the porosity of the polymer is predominant. (C) 2001 Else vier Science B.V. All rights reserved.