Automatic VIS- near IR laser refractometer

This work presents a simple automatic VIS-IR laser refractometer, based on a critical-angle method. Its experimental error is smaller than 6×10−4 within the range of 1.32–1.47. Such precision of the refractometer is sufficient for the most industrial applications, for environmental protection, structural analysis, investigation of new materials, etc. Spectral refractive index measurements of different liquids are led and the calculated dispersion coefficients are reported.