Nonlinear spectroscopy of molecules

Ch. Brunel, Philippe Tamarat, Brahim Lounis +1 more

Ch. Brunel, Philippe Tamarat, Brahim Lounis +1 more

F. Shikerman, Eli Barkai

We develop the theory of nonlinear spectroscopy for a single molecule undergoing stochastic dynamics and interacting with a sequence of two laser pulses. We find general expressions for the photon counting statistics and the exact solution to the problem for the Kubo-Anderson process. In the limit of impulsive pulses the information on the photon statistics is contained in the molecule's dipole correlation function. The selective limit, the semiclassical approximation, and the fast modulation limit exhibit rich general behaviors of this new type of spectroscopy. We show how the design of external fields leads to insights on ultrafast dynamics of individual molecules that are different from those found for an ensemble.

Wolfgang Demtröder

Wolfgang Demtröder

Xiaobo Xie, Ting Sun

The investigation of spectroscopy of vacuum ultraviolet (VUV, 100-200 nm) and extreme ultraviolet (XUV, 10-100 nm) regions has attracted the attention of many researchers in recent years because of its promising applications in such areas as spectroscopy of highly excited states of atoms and molecules, life science, plasma physics and material science. In this paper we report the study of molecular coherent spectrum in the VUV and XUV regions through nonlinear optical processes and the determination of the rotational temperature of molecules. Because molecular gases have abundant energy levels, it can provide resonant levels to enhance the generated radiation and a wide tunibility of the spectrum in VUV and XUV regions. The determination of the rotational temperature of molecules will be very useful for the study of molecular spectroscopy and the nonlinear optical process in VUV/XUV regions.