基于双环混合偏振矢量光束实现光学囚笼实时操纵的理论研究

理论上提出了一种通过调节双环混合偏振矢量光束的偏振态来实现光学囚笼实时操纵的新方法。双环混合偏振矢量光束是由双环径向光束通过一个波片后形成的,光束偏振将变为包含线偏振、圆偏振和椭圆偏振的混合状态,且偏振态强烈依赖于空间位置和相位延迟角度。利用衍射积分公式数值模拟了双环混合偏振矢量光束经过强聚焦系统后在焦点附近的强度分布。数值结果显示当相位延迟角度为0时能形成光学囚笼,当相位延迟角度不为0时能控制光学囚笼打开的程度。将液晶可调相位延迟器(LCVR)作为可调波片,LCVR可以由外部电压实时控制使其相位延迟角度能在0～π之间连续取值,这样就可以通过调节LCVR的外接电压实现焦平面光学囚笼的实时开和关。

Theoretical Study About Real-Time Manipulation of Optical Cage with Double-Ring-Shaped Hybridly Polarized Vector Beam

A new theoretical method of realizing real-time manipulation of the optical cage by changing the hybrid polarization states of a double-ring-shaped hybridly polarized vector beam is proposed. The hybrid polarization states can be formed by a double-ring-shaped radially polarized beam through a wave plate. The intensity distribution of the focused double-ring-shaped hybridly polarized vector beams is numerically simulated in the vicinity of the focal plane by using Richards-Wolf vectorial diffraction method. The results show that the optical cage can be formed when the phase delay angle is zero, and the optical cage can be real-time manipulated when the phase delay angle is not zero. The polarization state can be changed by adjusting the phase delay angle of the liquid crystal variable retarder, which can be continuously varied from 0 to π. The realization and manipulation of the optical cage in real time aroused by the phase delay angle will have great potential applications in the field of micro-manipulation.