Zhong Min-Cheng, Zhou Jin-Hua, Ren Yu-Xuan, Li Yin-Mei, Wang Zi-Qiang
Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Appl Opt. 2009 Aug 1;48(22):4397-402. doi: 10.1364/ao.48.004397.
Birefringent particles rotate when trapped in elliptically polarized light. When an infinity corrected oil-immersion objective is used for trapping, rotation of birefringent particles in optical tweezers based on an infinity optical microscope is affected by the spherical aberration at the glass-water interface. The maximum rotation rate of birefringent particles occurs close to the coverslip, and the rotation rate decreases dramatically as the trapped depth increases. We experimentally demonstrate that spherical aberration can be compensated by using a finite-distance-corrected objective to trap and rotate the birefringent particles. It is found that the trapped depth corresponding to the maximum rotation rate is 50 microm, and the rotation rates at deep trapped depths are improved.
双折射粒子被困在椭圆偏振光中时会发生旋转。当使用无限远校正油浸物镜进行捕获时，基于无限远光学显微镜的光镊中双折射粒子的旋转会受到玻璃 - 水界面处球差的影响。双折射粒子的最大旋转速率出现在靠近盖玻片的位置，并且随着捕获深度的增加，旋转速率会急剧下降。我们通过实验证明，可以使用有限距离校正物镜来捕获和旋转双折射粒子，从而补偿球差。发现对应最大旋转速率的捕获深度为50微米，并且在较深捕获深度处的旋转速率得到了提高。
