Preparation and application of a novel chemical sensor based on mode-filtered light detection

A novel mode-filtered Light chemical sensor is reported. This sensor operat es by the detection of the mode-filtered light emanating from an uncoated o ptical fiber based on the changes of analyte refractive index. Compared to measuring changes in the transmitted light at the end of the fiber optic, i t has great advantage in signal-to-noise ratio against a low background. A good result is obtained by detecting ethanol in alcohol solutions within th e ethanol concentration range of 0-50% (v/v) (r = 0.9972). The sensor is al so applied to the measurement of the sample spirit, and the result is satis factory. (C) 2000 Elsevier Science S.A. All rights reserved.