A technique for contactless measurement of water temperature using Stokes and anti-Stokes comparative Raman spectroscopy

Contactless measurements of water temperature are utilized in a number of sciences, such as oceanography, climatology, and biology. Previously reported Raman spectroscopy techniques exploited the changes in the shapes of water Raman bands. Interpretation of these changes is difficult since these bands are composed of multiple lines, each influenced not only by temperature but also by pressure and salinity. This paper presents a proof-of-principal demonstration of a contactless technique which determines water temperature from the ratio of Stokes and anti-Stokes intensities of the water 180 cm−1 Raman band. This ratio is not sensitive to pressure and salinity, allowing reliable determination of water temperature.