Zhong Min-Cheng, Wang Zi-Qiang, Li Yin-Mei
Appl Opt. 2017 Mar 1;56(7):1972-1976. doi: 10.1364/AO.56.001972.
Optical tweezers have been used to trap and manipulate microparticles within living animals. When the optical trap is constructed with an oil-immersion objective, it suffers from spherical aberration. There have been many investigations on the influence of spherical aberration when the particles are trapped in a water medium. However, the dependence of optical force on trapping depth is still ambiguous when the trapped particles are immersed in a high refractive index medium (such as biological tissue, refractive index solution) in experiments. In this paper, the microparticles are immersed in an aqueous solution of glycerol to mimic the cells within biological tissue. As the trapping laser is focused into the specimen, spherical aberration is introduced, degrading the optical trapping performance. It is similar to trapping in water; altering the effective tube length can also compensate for the spherical aberration of the optical trap in a high refractive index medium. Finally, the cells in living mice are trapped by the optical tweezers with the help of spherical aberration compensation.
光镊已被用于捕获和操纵活体动物体内的微粒。当使用油浸物镜构建光阱时，会出现球差。对于在水介质中捕获微粒时球差的影响已经有很多研究。然而，在实验中当捕获的微粒浸没在高折射率介质（如生物组织、折射率溶液）中时，光力对捕获深度的依赖性仍然不明确。在本文中，将微粒浸没在甘油水溶液中以模拟生物组织内的细胞。当捕获激光聚焦到样本中时，会引入球差，从而降低光镊的性能。这与在水中捕获类似；改变有效光管长度也可以补偿高折射率介质中光阱的球差。最后，在球差补偿的帮助下，用该光镊捕获了活体小鼠体内的细胞。
