Wan Lipeng, Zhao Daomu
Opt Lett. 2019 Feb 15;44(4):735-738. doi: 10.1364/OL.44.000735.
Optical twists are the rotation of light structures along the beam axis, which can be caused by the quadratic twist phase of a partially coherent field. Here, we introduce a new class of partially coherent beams whose spectral density and degree of coherence tend to rotate during propagation. Unlike the previously reported twisted Gaussian Schell-model beams, this family of rotating beams is constructed without the framework of rotationally invariant cross-spectral density functions. Thus, these beams have different underlying physics and exhibit distinctive twist effects. It is shown that such beams can undergo a twist of more than 90 deg, providing larger degrees of freedom for flexibly tailoring the beam twist. Our results may pave the way toward synthesizing rotating beams for applications in optics and, in particular, inspire further studies in the field of twist phase proposed 25 years ago.
光学扭曲是指光结构沿光束轴的旋转，这可能由部分相干场的二次扭曲相位引起。在此，我们引入了一类新型的部分相干光束，其光谱密度和相干度在传播过程中趋于旋转。与先前报道的扭曲高斯谢尔模型光束不同，这类旋转光束的构建无需旋转不变交叉谱密度函数的框架。因此，这些光束具有不同的基础物理特性，并呈现出独特的扭曲效应。结果表明，此类光束可产生超过90度的扭曲，为灵活调整光束扭曲提供了更大的自由度。我们的研究结果可能为合成用于光学应用的旋转光束铺平道路，特别是激发对25年前提出的扭曲相位领域的进一步研究。
