The optical needle generated by a tightly focused vector optical field (VOF) has attracted wide attention and been applied in various areas. In previous research, two typical kinds of VOFs were generally used to generate optical needles, including radially polarized VOF (RP-VOF) and vortex azimuthally polarized VOF (VAP-VOF). Here, we propose a new kind of duplex VOF that is designed by arranging the RP-VOF and VAP-VOF in concentric belts. With the help of a binary phase mask, the optical needle of the tightly focused duplex VOF is much longer than that generated by the two conventional VOFs. The optical needle has a three-section polarization distribution, as the longitudinal component is dominant in the center, while the transverse components are at two ends along the longitudinal axis, which is different from a purely transversely polarized optical needle and optical needle with a dominant longitudinal component. Furthermore, a parabolic hybrid mask (PHM) is proposed, which can improve the length of the optical needle for the duplex VOF, RP-VOF, and VAP-VOF. When applying the duplex VOF and PHM simultaneously, an ultra-long optical needle can be achieved. The duplex VOF and PHM we propose are superior relative to other VOFs and masks in terms of generating ultra-long optical needles, which can be used in areas including optical detection, high-density storage, super-resolution imaging, and nano lithography.

中文翻译：

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用双工矢量光场和抛物线混合掩模实现超长光学针

由紧密聚焦矢量光场（VOF）产生的光针引起了广泛关注并被应用于各个领域。在以往的研究中，通常使用两种典型的VOF来产生光针，包括径向偏振VOF（RP-VOF）和涡旋方位偏振VOF（VAP-VOF）。在这里，我们提出了一种新型双工 VOF，它是通过将 RP-VOF 和 VAP-VOF 排列在同心带中而设计的。在二元相位掩模的帮助下，紧密聚焦的双工 VOF 的光学针比两个传统 VOF 产生的光学针长得多。光针具有三段偏振分布，因为纵向分量在中心占主导地位，而横向分量在沿纵轴的两端，这与纯横向偏振光针和具有主导纵向分量的光针不同。此外，还提出了抛物线混合掩模（PHM），它可以提高双工 VOF、RP-VOF 和 VAP-VOF 的光学针长度。同时应用双工VOF和PHM时，可以实现超长光学针。我们提出的双工VOF和PHM在产生超长光学针方面优于其他VOF和掩膜，可用于光学检测、高密度存储、超分辨率成像和纳米光刻等领域。同时应用双工VOF和PHM时，可以实现超长光学针。我们提出的双工VOF和PHM在产生超长光学针方面优于其他VOF和掩膜，可用于光学检测、高密度存储、超分辨率成像和纳米光刻等领域。同时应用双工VOF和PHM时，可以实现超长光学针。我们提出的双工VOF和PHM在产生超长光学针方面优于其他VOF和掩膜，可用于光学检测、高密度存储、超分辨率成像和纳米光刻等领域。