偏振方向对涡旋光束产生的影响

Influence of polarization direction on vortex beam

在利用液晶空间光调制器(LCSLM)产生涡旋光束时,入射光的偏振方向对涡旋的产生有着明显的影响。从液晶空间光调制器的工作原理出发,研究了不同偏振方向的线偏振光在通过LCSLM的相位调制后,涡旋光束产生的变化。通过模拟仿真与实验结果的比较,发现随着线偏振光的偏振方向与液晶分子光轴夹角的增大,液晶空间光调制器的调制误差变大,所产生的涡旋光束的质量变差。当夹角大于4.725°时,涡旋光束的质量明显变差。而随着夹角继续增大,LCSLM对入射光的调制作用减弱,无法产生涡旋光束。

When a vortex beam is generated by liquid crystal spatial light modulator（LCSLM）,the polarization direction of the incident light has a significant effect on generating the vortex.Based on the physical principle of the spatial light modulator,the influence of the polarization directions of the incident light on the output beam is calculated and analyzed,and the calculation is compared with the experimental results.The results show that,the modulation error of the LCSLM increases with the angleαbetween the polarization direction of the incident light and the optical axis of the liquid crystal molecule,and the quality of vortex beam is worse.In particular,the quality of the vortex beam is significantly worse when the angleαis greater than 4.725°.As the angle continues to increase,the modulation effect of LCSLM on the incident light is weakened,and the vortex beam can not be generated.