Optical Kerr Effect of Water from Liquid States into the Supercooled Regime
Ping-Han Tang1*, Ten-Ming Wu1
1institude of physics, National Chiao-Tung University, Hsinchu, Taiwan
* presenting author:Ping-Han Tang, email:pinhamtang@gmail.com
Recently, the time-resolved optical-Kerr-effect (OKE) spectroscopy of supercooled water has been measured with femtosecond laser pluses and heterodyne detection. Theoretically, the OKE spectrum is the imaginary part of Fourier transform of the nuclear response function, which can be obtained from the time derivative of the polarizability anisotropy time correlation function. In this study, we investigated the OKE of bulk water from liquid states into the supercooled regime by using MD simulations for the SPC/E model and a dipolar induction scheme that involves the intrinsic polarizability and first hyperpolarizability tensor of a water molecule. The OKE spectrum of supercooled water consisted of three bands, which were related to the respective behaviors of the nuclear response function at short, intermediate and long times. The contributions of the intrinsic polarizability of individual molecules and the dipole-induced-dipole mechanism to the nuclear response function of water will be discussed.

Keywords: water, optical Kerr effct, supercooled, nuclear reponse function