Influence of femtosecond dephasing on CARS coherence in various approximations

Svetlana Malinovskaya

H. Nishioka, Kenji Ueda

Vladimir S. Malinovsky

We demonstrate the adiabatic passage based method to maximize CARS coherence and present numerical results of the roof scheme implementation without making an assumption of adiabatic elimination of detuned excited electronic states. Also we analyze influence of fast decoherence in the molecular samples on the results of proposed scheme. It is shown that the adiabatic method allows achieving chemical sensitivity with high resolution and can be used to obtain CARS signal with efficiently suppressed background in molecular systems with coherence times of several hundred of femtoseconds.

Shian Zhang, Hui Zhang, Tianqing Jia +2 more

In this paper, we present a feasible method to realize and improve the selective excitation of femtosecond coherent anti-Stokes Raman scattering (CARS) in a mixture. We theoretically show that, by shaping both the pump and probe pulses with the pi phase step, the CARS signal from one quantum system can be enhanced and simultaneously that from the other quantum system is effectively suppressed. Comparing with only shaping the probe pulse [D. Oron, N. Dudovich, D. Yelin, and Y. Silberberg, Phys. Rev. Lett., 88, 063004 (2002)], the selectivity of femtosecond CARS by shaping both pump and probe pulses can be greatly improved. Finally, we experimentally compare two shaping schemes by investigating the selective excitation of the femtosecond CARS in the mixture of dibromomethane (CH(2)Br(2)) and chloroform (CHCl(3)).

Anand T. N. Kumar

Dai‐Sik Kim