光子学报, 2019, 48 (7): 0726002, 网络出版: 2019-07-31
不同偏振态光镊三维光阱刚度的比较研究
Comparison Investigation of the Three-dimensional Stiffness of Optical Tweezers with Different Polarization Fields
光阱刚度 偏振态 折射率 球差 数值孔径 Optical trap stiffness Polarization state Refractive index Spherical aberration Numerical aperture
摘要
为了研究激光偏振态对光阱刚度的影响, 本文比较了四种不同偏振态光场(方位角偏振光、径向偏振光、线偏振光、圆偏振光)捕获不同尺寸SiO2微粒的三维光阱刚度.研究结果表明:当SiO2微粒的尺寸和激光波长相近时, 圆偏振光和线偏振光的三维光阱刚度大于径向偏振光和方位角偏振光的三维光阱刚度; 而随着SiO2微粒尺寸的增加, 方位角偏振光和径向偏振光的三维光阱刚度大于圆偏振光和线偏振光的三维光阱刚度.此外, 实验也表明:使用浸油物镜捕获微粒时, 物镜匹配油的折射率和水的折射率不一致引起的球差, 会降低系统对物镜数值孔径的利用.通过这些研究工作, 可以为不同偏振态光场的测力研究提供一定的指导和参考.
Abstract
To elucidate the influence of laser polarization state on optical trap stiffness, the three-dimensional stiffness of four kinds of optical traps with different polarization states (azimuthally polarized beam, radially polarized beam, linearly polarized beam, and circularly polarized beam) to trap silica beads with different sizes was investigated. The result show that, when the silica bead's size is equivalent to the laser wavelength, the three-dimensional stiffness of circularly polarized beam and linearly polarized beam are larger than those of radially polarized beam and azimuthally polarized beam. With the increase of the silica bead's size, the three-dimensional stiffness of azimuthally polarized beam and radially polarized beam are larger than those of circularly polarized beam and linearly polarized beam. In addition, the experimental results also show that, when using an oil-immersion objective lens to trap particles, the spherical aberration caused by the mismatch of the refractive index of oil and water will reduce the utilization of the numerical aperture of the objective lens. The work reported in this paper provides a guidance and reference to the force measurement when using trapping beams with different polarization states.
曹志良, 梁言生, 严绍辉, 周源, 蔡亚楠, 雷铭, 李曼曼, 姚保利. 不同偏振态光镊三维光阱刚度的比较研究[J]. 光子学报, 2019, 48(7): 0726002. CAO Zhi-liang, LIANG Yan-sheng, YAN Shao-hui, ZHOU Yuan, CAI Ya-nan, LEI Ming, LI Man-man, YAO Bao-li. Comparison Investigation of the Three-dimensional Stiffness of Optical Tweezers with Different Polarization Fields[J]. ACTA PHOTONICA SINICA, 2019, 48(7): 0726002.