Nonlinear Waveguide Sensor for the Determination of the Refractive Index of Liquids in the Near Infrared

The knowledge of the refractive index of liquids is of major importance in many application fields and therefore several methods have been proposed to achieve high precision and accuracy. Although most methods can in principle be used both in the visible and in outer ranges (e g. in the infrared), they have typically been tested only in the visible, mainly due to experimental difficulties, and values in the infrared have been obtained by extrapolation.