Determination of Ethanol Concentration by Raman Spectroscopy in Liquid-Core Microstructured Optical Fiber

A liquid-core air-clad microstructured fiber has been developed for determination of ethanol and sucrose concentrations in aqueous solutions by Raman spectroscopy. The fiber, the light and liquid injection method as well as the measurement system are described in details. The sensor has been calibrated using a set of binary solutions and the extracted model was validated on a set of ethanol sucrose solutions. A good agreement is found between the measured and expected concentration values. Preliminary results on the application of the sensor to white wine characterization are also presented. The configuration used for injection is stable and robust, making the sensor useful for online measurements.