2007/06/16 by Hong-tao Bian, Yi Rao, Bian, Hong-tao +9
Physics and Astronomy · #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Optics (physics.optics) #physics.chem-ph #physics.optics
paper · pdf · doi:10.48550/arxiv.0706.2408
4 pages, 4 figures
arxiv created 2007/06/16 · arxiv updated 2009/12/01
Unexpected spectral features are observed in the two photon spectrum of the pure water in the forward direction when an 80 femtosecond laser pulse is focused at 1010Wcm-2 or less. Such intensity is much lower than the breakdown or stimulated threshold of the liquid water. The two broad features are about 2700cm-1 and 5000cm-1 red shifted from the hyper-Rayleigh wavelength, respectively, and they are quadratic with the laser intensity. They do not match the known Raman or hyper-Raman frequencies of water, and they are both centered at a narrow angle in the forward direction. Several other liquids also exhibited similar but molecular specific spectral features.