Abstract We theoretically demonstrate a transversely polarized ultra-long optical needle with lateral width beyond diffraction limit generated by tight focusing of a cylindrical polarized circular Airy Gaussian vortex beam (CAiGVB). According to the calculation expression derived through the Richard-Wolf diffraction theory, the properties of optical needles are investigated in simulation in detail. The analysis reveals that the interaction between the vortex phase and the state of polarization of the CAiGVB through tight focusing results in the generation of the transversely polarized optical needles. The depth of the optical needle is strongly affected by the maximum position of the brightest ring, the optical distribution factor and the truncation factor of the CAiGVB. However, the lateral width of optical needle is only influenced by the maximum position of the brightest ring. The simulation results indicate that an optical needle of longitudinal length 38 λ with lateral width of only 0.46 λ can be achieved. To improve the intensity uniformity of longitudinal direction, a method of the combination of tight focusing with a binary phase element is used Such a transversely polarized optical needle has significant potential in atomic trapping and ultrahigh density magnetic storage.

中文翻译：

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圆柱偏振圆形艾里高斯涡旋光束产生的横向偏振超长光针

摘要 我们从理论上证明了一种横向偏振超长光学针，其横向宽度超过了由圆柱形偏振圆形艾里高斯涡旋光束 (CAiGVB) 紧密聚焦产生的衍射极限。根据Richard-Wolf衍射理论推导出的计算表达式，对光学针的特性进行了详细的仿真研究。分析表明，涡旋相位与 CAiGVB 偏振状态之间的相互作用通过紧密聚焦导致产生横向偏振光针。光针的深度受最亮环的最大位置、CAiGVB 的光分布因子和截断因子的强烈影响。然而，光针的横向宽度只受最亮环最大位置的影响。仿真结果表明，可以实现纵向长度为 38 λ、横向宽度仅为 0.46 λ 的光学针。为了提高纵向强度的均匀性，采用了紧密聚焦与二元相位元件相结合的方法。这种横向偏振光针在原子俘获和超高密度磁存储方面具有巨大的潜力。