泽尼克多项式校正全息阵列光镊像差的实验研究

像差会影响光镊对粒子的捕获效果. 全息阵列光镊中, 像差不仅来自光学元件, 由特定算法设计的光阱相位片也会在光路中引入像差. 本文通过液晶空间光调制器加载泽尼克多项式相位图, 对全息阵列光镊中由光栅透镜组型算法引起的像差进行校正. 结果显示: 利用三阶泽尼克多项式可有效消除光路中由光栅透镜组型算法引 起的慧差, 使得捕获2 μm聚苯乙烯小球的阵列光阱刚度提高了约40%; 对比不同项的像差校正结果发现, 全息阵列光镊中由算法引起的慧差 与光学元件引起的像差一样, 也会对阵列光阱的捕获效果产生较大影响; 同时根据一阶像差校正结果可得光栅透镜 组型算法对于一阶泽尼克像差具有鲁棒性. 实验结果表明, 对全息阵列光镊中由 算法引起的像差进行校正, 对于提高光阱的捕获效果和深化对算法特性的认识都具有重要意义.

Aberrations in holographic array optical tweezers corrected with Zernike polynomials

Aberrations will degrade trapping performance of optical tweezers.In the holographic optical tweezers,aberrations originate not only from optical elements but also from holographic phase hologram of optical traps designed by a certain algorithm.We utilize a spatial light modulator to imprint Zemike polynomials phase hologram for correcting some certain aberrations in holographic array optical tweezers which are caused by grating and lens algorithm.The results show that third-order Zemike term can effectively correct coma due to the algorithm in the optical train,and the trap stiffness for 2μm microns diameter polystyrene beads can reach 40%. Further comparison between different Zemike term aberration correction effects demonstrates that coma caused by grating and lens algorithm in the holographic array optical tweezer has the same serious influence on tweezer trapping performance as the aberrations originating from optical elements.Meanwhile,based on first-order Zemike term aberration correction results it can be obtained that grating and lens algorithm are robust with first-order Zernike aberrations.The correcting of aberrations for algorithm in holographic optical tweezers has great significance for improving the tweezer trapping performance and deepening the understanding of specific algorithm.