Department of Physics and State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, People's Republic of China.
J Chem Phys. 2010 Jan 28;132(4):044505. doi: 10.1063/1.3298859.
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)).
在本文中,我们提出了一种可行的方法来实现和改进飞秒相干反斯托克斯拉曼散射(CARS)在混合物中的选择性激发。我们从理论上表明,通过用π相阶对泵浦和探测脉冲进行整形,可以增强来自一个量子系统的 CARS 信号,同时有效抑制来自另一个量子系统的 CARS 信号。与仅对探测脉冲进行整形相比[D. Oron、N. Dudovich、D. Yelin 和 Y. Silberberg,Phys. Rev. Lett.,88,063004(2002)],通过对泵浦和探测脉冲进行整形可以大大提高飞秒 CARS 的选择性。最后,我们通过研究二溴甲烷(CH(2)Br(2))和三氯甲烷(CHCl(3))混合物中飞秒 CARS 的选择性激发,实验比较了两种整形方案。