Lu Chenhui, Yao Yunhua, Xu Shuwu, Jia Tianqing, Ding Jingxin, Zhang Shian, Sun Zhenrong
State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University , Shanghai 200062, People's Republic of China.
J Phys Chem A. 2014 Jun 26;118(25):4480-3. doi: 10.1021/jp502324p. Epub 2014 Jun 13.
We theoretically and experimentally demonstrate the control of the intermediate state absorption in (1+2) resonance-mediated multiphoton absorption process by shaping the femosecond laser pulse. A theoretical model is proposed to investigate the intermediate state absorption of (1+2) resonance-mediated three-photon absorption process in the molecular system, and an analytical solution is obtained on the basis of time-dependent perturbation theory. Our theoretical results show that the intermediate state absorption can be enhanced by controlling the laser spectral phase due to final state absorption reduction, and this absorption enhancement efficiency increases with the increase of the laser intensity. These theoretical results are experimentally confirmed in IR144 dye by varying the laser spectral phase with a sinusoidal modulation function.
我们通过对飞秒激光脉冲进行整形，从理论和实验上证明了在（1+2）共振介导的多光子吸收过程中对中间态吸收的控制。提出了一个理论模型来研究分子系统中（1+2）共振介导的三光子吸收过程的中间态吸收，并基于含时微扰理论得到了解析解。我们的理论结果表明，由于终态吸收的减少，通过控制激光光谱相位可以增强中间态吸收，并且这种吸收增强效率随着激光强度的增加而提高。通过用正弦调制函数改变激光光谱相位，这些理论结果在IR144染料中得到了实验证实。
