In this paper, we investigate the generation and controlling of the optical vortex beam using a dye-doped liquid crystal (DDLC) cell. The spatial distribution of the quasi-sinusoidal orientation of the liquid crystal molecules creates a quasi-sinusoidal phase grating (PG) in the DDLC cell. Depending on the incident light pattern, Trans to Cis photoisomerization of the dye molecules affects the orientation of the liquid crystal molecules. To do so, an amplitude fork grating (FG) is used as a mask, and its pattern is stored in the cell by a pattern printing method as the PG. One of the particular features of the stored grating in the cell is its capability in the diffraction efficiency controlled by the applied electric field. The results show, based on the central defect in the FG pattern, the diffracted probe beam in different orders is optical vortices. As a new technique, this type of stored pattern acts like an amplitude grating but according to the results, its structure is in fact a PG. This technique leads to the vortex beam switching capability by applying an electric field to the cell. The results show that by applying 22 V, all the diffraction orders vanish. Meanwhile, the vortex beams reappear by removing the applied voltage. The diffraction efficiency of the vortex beams as well as its generation dependency on the polarization of the incident beam studied. The maximum efficiency of the first diffraction order for linear polarized incident beam was obtained at 0 V, about 8%. Based on the presented theory, a simulation has been done which shows the Cis form of the dye molecules has been able to change the angle of LC molecules on average about 12.7°. The study of diffracted beam profiles proves that they are electrically controllable vortex beams.

在本文中，我们使用染料掺杂液晶 (DDLC) 单元研究了光学涡旋光束的产生和控制。液晶分子准正弦取向的空间分布在 DDLC 单元中产生准正弦相位光栅 (PG)。根据入射光模式，染料分子的反式到顺式光异构化影响液晶分子的取向。为此，振幅叉光栅（FG）被用作掩模，其图案作为PG通过图案印刷方法存储在单元中。单元中存储的光栅的一个特殊特征是其衍射效率受施加电场控制的能力。结果表明，基于 FG 图案中的中心缺陷，不同阶次的衍射探测光束是光学涡旋。作为一种新技术，这种存储模式的作用类似于振幅光栅，但根据结果，它的结构实际上是一个 PG。该技术通过向电池施加电场来产生涡流束切换能力。结果表明，通过施加 22 V，所有衍射级都消失了。同时，通过移除施加的电压，涡流束重新出现。研究了涡旋光束的衍射效率及其对入射光束偏振的产生依赖性。线性偏振入射光束的第一衍射级的最大效率在 0 V 时获得，约为 8%。基于提出的理论，已进行的模拟显示染料分子的顺式形式能够平均改变 LC 分子的角度约 12.7°。衍射光束剖面的研究证明它们是电控涡旋光束。