Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (5): 836-844.doi: 10.3866/PKU.WHXB201403262

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Influences of Molecular Rotations and Laser Pulses on Controlling Multiphoton Excitation

FENG Hai-Ran1, LI Peng1, ZHENG Yu-Jun2, WANG De-Hua3   

  1. 1 Department of Physics and Information Engineering, Jining University, Qufu 273155, Shandong Province, P. R. China;
    2 School of Physics, Shandong University, Jinan 250100, P. R. China;
    3 School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, Shandong Province, P. R. China
  • Received:2013-12-30 Revised:2014-03-25 Published:2014-04-25
  • Contact: FENG Hai-Ran E-mail:hrfeng_jnxy@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11147019, 91021009, 11374133).

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Abstract:

The influence of molecular rotation, laser pulse shape and initial phase on controlling the infrared multiphoton excitation of diatomic molecules has been studied using an analytical algebraic approach, which involved the derivation of analytic transition probabilities with various rotational channels. To observe the correctional functions of the rotational energy and the relationship between the molecular orientation and the polarized direction of the laser field in terms of their impact on controlling multiphoton excitation, we calculated the probabilities in the purely vibrational and ro-vibrational cases. The maximumtransition probabilities were determined as a function of the time and molecular orientation angle in both cases for comparison, which allowed for the target multiphoton excitations to be achieved. However, oscillations appeared in the population of the ro-vibrational case which denoted rotational interference can decrease the selectivity of the molecular vibrational excitation. Furthermore, the rotational energy had a corrected action on multiphoton non-resonant excitation and the power of actions was dependent on the molecular anharmonicity. We have also provided a discussion of the influences of laser pulse shape and initial phase. We found that the use of an appropriate laser pluse shape afforded the target multiphoton excitation event, and that the initial phase of the chirped laser pulse had an obvious modulatory function on the multiphoton processes.

Key words: Multiphoton, Molecule, Excitation, Control, Lie-algebra

MSC2000: 

  • O644.1