AI 中文总结
研究通过光学涡旋衍射实现光学空心陷阱可控定位与操纵，基于入射LG光束模型，通过改变屏幕边缘位置控制衍射场中OV核心位置，可实现亚纳米精度运动，分析了相关影响因素及微物体捕获操纵的有利条件。
AI 中文摘要
光学涡旋（OV）与局部强度零耦合，适用于“空心”光学陷阱和光镊。当入射圆形OV光束在直线屏幕边缘（SE）发生衍射且满足弱衍射扰动条件时，主要结果是OV核心从其初始（轴向）位置位移。基于入射拉盖尔 - 高斯（LG）光束模型，通过改变SE相对于入射光束轴的位置，对控制衍射场横截面中OV核心位置的方法进行了分析和数值研究。结果表明，以约1μm的精度调节SE位置（现有机械工具可实现），可实现亚纳米精度的可控OV核心运动。分析了该运动随入射光束拓扑电荷、波前曲率、SE特性（半透明屏幕、相位阶梯屏幕）以及衍射平面与观察平面之间距离的可能变化。指定并讨论了最有利于微物体捕获和操纵的条件。
英文摘要
An optical vortex (OV) is coupled with the local intensity zero and is thus a field configuration suitable for "hollow" optical traps and optical tweezers. When an incident circular OV beam experiences diffraction at a rectilinear screen edge (SE), and the conditions of weak diffraction perturbation (the SE is far enough from the beam axis) are fulfilled, the main consequence is the OV-core displacement from its initial (axial) position. Based on the model of incident Laguerre-Gaussian (LG) beam, we investigate analytically and numerically the ways of controlling the OV-core position in the diffracted-field cross section by means of changing the SE position with respect to the incident-beam axis. The results show that regulating the SE position with ~1 mcm accuracy (which is available for existing mechanical tools), controllable OV-core motion with a sub-nanometer accuracy can be realized. Possible modifications of this motion depending on the incident beam topological charge, wavefront curvature, SE properties (semitransparent screen, phase-step screen) and the distance between the diffraction plane and the observation plane are analyzed. The conditions most favorable for the micro-object trapping and manipulation are specified and discussed.
Comments13 pages, 4 figures
