Orienting CO molecules with an optimal combination of THz and laser pulses: Optimal control simulation with specified pulse amplitude and fluence
Orienting CO molecules with an optimal combination of THz and laser pulses: Optimal control simulation with specified pulse amplitude and fluence
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DOI：
10.1103/physreva.90.013415
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发表时间：
2014-07
影响因子：
2.9
通讯作者：
Masataka Yoshida;Y. Ohtsuki
中科院分区：
文献类型：
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作者：
Masataka Yoshida;Y. Ohtsuki
应用线性(偶极)和非线性(极化率)相互作用的脉冲幅度和注量的最优控制模拟方法，找到了用THz和激光脉冲组合来定向CO分子的最佳方法。在温度范围和温度范围内，最佳脉冲的数值设计具有指定的太赫兹脉冲的最大幅度和指定的激光脉冲的通量。最佳脉冲几乎总是由一个接近单周期的零面积太赫兹脉冲和一个主要由三个子脉冲组成的激光脉冲组成。在太赫兹脉冲和激光子脉冲之间没有时间重叠。太赫兹脉冲实际上不包含直流分量，它以共振的方式诱导转动跃迁，而三个激光子脉冲通过拉曼散射有效地诱导多个转动跃迁。对比有无激光脉冲的最优控制模拟，激光脉冲通过与反转对称性的偏振性相互作用有效地将取向度数提高了近一半。
Pulse-amplitude and fluence-specified optimal control simulation with linear (dipole) and nonlinear (polarizability) interactions is applied to find the best way to orient CO molecules with a combination of THz and laser pulses. The optimal pulses are numerically designed with a specified maximum amplitude of the THz pulse and a specified fluence of the laser pulse within the ranges ofandat temperature. The optimal pulse almost always consists of a near-single-cycle THz pulse of zero area and a laser pulse that is mainly composed of three subpulses. There is no temporal overlap between the THz pulse and the laser subpulses. The THz pulse, which virtually contains no dc components, induces rotational transitions in a resonant way, whereas the three laser subpulses efficiently induce multiple rotational transitions through Raman scattering. Comparing the optimal control simulations with and without laser pulses, the laser pulses effectively increase the degrees of orientation by approximately half through the polarizability interaction with inversion symmetry.