2-DIMENSIONAL THZ SPECTROSCOPY OF LIQUIDS - NONLINEAR VIBRATIONAL RESPONSE TO A SERIES OF THZ LASER-PULSES

We propose a non-linear experiment using the non-linear interaction wi th THz pulses, the generation of which has recently become well establ ished. In the lowest non-linear process, we have two controllable dela y times. This is another optical analogue of two-dimensional (2D) NMR as the recently developed 2D Raman spectroscopy. Our model calculation for liquid water demonstrates the striking capability of the proposed technique, clearly distinguishing two types of anharmonicity in the l ow-frequency modes. (C) 1998 Elsevier Science B.V. All rights reserved .