What Do We Do ?

 Our group at the Department of Chemical Physics at the Weizmann Institute of Science studies various aspects of light matter interaction and nonlinear laser spectroscopy.  Using ultrafast lasers we excite molecules on time scales faster than their internal motion (vibrational and rotational), and try to develop spectroscopic approaches to study molecular behavior on these short time scales.  These short pulses are used to align molecules in space, to selectively excite close molecular  species in a mixture, and to manipulate molecules at will.  In another project we are developing spectroscopic tools at the interface between the time and frequency domains, in an attempt to maximize the information extracted from a particular experimental situation.  We have developed a new approach to the measurement of an entire spectrum within a single shot, and are pursuing these developments for more sophisticated applications.  In another direction, we are using optical near field approaches to modify surfaces on the nanometer scale, where an external laser beam irradiates the tip of an AFM  and both the hot tip and the concentrated electric field under it  are used for surface modification.  Large molecules at the liquid air interface are also studied, in an attempt to induce two dimensional crystallization towards better options for the study of larger crystals.  We focus our attention on the nonlinear optical interactions, and are constantly looking for new approaches and new spectroscopic methods.