Optically induced inter-particle forces: from the bonding of dimers to optical electrostriction in molecular solids
Optically induced inter-particle forces: from the bonding of dimers to optical electrostriction in molecular solids
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DOI：
10.1088/0953-4075/39/15/s11
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发表时间：
2006-08
期刊：
影响因子：
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通讯作者：
D. Andrews;Richard G. Crisp;D. S. Bradshaw
中科院分区：
文献类型：
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作者：
D. Andrews;Richard G. Crisp;D. S. Bradshaw
Casimir-Polder相互作用的量子电动力学公式引起了对光致粒子间力的考虑，这在同一水平的微扰理论中出现。为了观察这种效应，对耦合机制的定量评估表明，现在通常可从脉冲激光器获得的强度水平。在本文中，一个理论分析的主要机制，其次是两个具体的系统，选择说明广泛的意义和系统的范围，这种影响可能是明显的发展。第一个系统是一个货车范德华二聚体，一个松散的约束和基本上孤立的分子对，其中一个小的光学诱导的位移的平衡键长证明是很好的测量范围内的微波旋转光谱。第二个系统示出了相反的极端，在那里的光诱导的修改密集堆积的分子之间的凝聚相的力被示出产生各向异性图案的激光诱导的压缩和膨胀，被称为光电致伸缩的效果。同样，这种影响应该是容易衡量的，尽管必要的条件是，也可能产生一些次级影响。排除这些二次效应在凝聚相和明确识别光学诱导分子间力的实验挑战进行了讨论。可能的应用也受理，包括纳米机电系统的光学执行器。
The quantum electrodynamical formulation of the Casimir–Polder interaction invites a consideration of optically induced inter-particle forces, which arise in the same level of perturbation theory. For the observation of such effects, quantitative assessments of the coupling mechanism suggest levels of intensity that are now routinely available from pulsed lasers. In this paper, a theoretical analysis of the principal mechanism is followed by a development for two specific systems, chosen to illustrate the broad significance and the range of systems in which such effects might be manifest. The first system is a van der Waals dimer, a loosely bound and essentially isolated molecular pair in which a small optically induced shift in the equilibrium bond length proves to be well within the limits of measurement by microwave rotational spectroscopy. The second system illustrates the opposite extreme, where an optically induced modification of the forces between densely packed molecules in the condensed phase is shown to produce anisotropic patterns of laser-induced compression and expansion, an effect termed optical electrostriction. Again, such an effect should be readily measurable, although the necessary conditions are such that a number of secondary effects might also be likely to arise. The experimental challenge of precluding those secondary effects in the condensed phase and unequivocally identifying optically induced intermolecular forces is discussed. Possible applications are also entertained, including optical actuators for nanoscale electromechanical systems.