RESUMEN
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.
Asunto(s)
Espectrometría Raman/métodos , Temperatura , Agua/química , Rayos Infrarrojos , Espectrometría Raman/instrumentaciónRESUMEN
We report guiding of sub-100-fs pulses at intensities up to 5x10(15) W/cm (2) over a distance of 1 cm in a preformed plasma channel. The width of the guided pulse was shortened, which we attribute to ionization-induced refraction at the channel entrance. A pulse energy throughput of 30% in the lowest-order was measured.