An interferometric arrangement that automatically compensates for thermal expansion was used to examine the changes in the refractive index of liquid water at 632.8 nm as a function of temperature from 10 to −15 °C. By combining the results of this research with existing data, we calculated the absolute refractive index in the supercooled region with an accuracy ranging from 3 × 10<sup>−6</sup> to 1 × 10<sup>−5</sup>. A direct observation of the refractive-index maximum of water is reported for the first time to our knowledge and found to occur between 0 and 0.1 °C.
© 2002 Optical Society of America
Lee Carroll and Martin Henry, "Autocompensating Interferometer for Measuring the Changes in Refractive Index of Supercooled Water as a Function of Temperature at 632.8 nm," Appl. Opt. 41, 1330-1336 (2002)