Opt Lett. 2018 Dec 15;43(24):5981-5984. doi: 10.1364/OL.43.005981.
Vector beams have been extensively investigated in recent years because of their fascinating vector character across the beam transverse section, which is demonstrated to be useful for optical micro-manipulation, optical micro-fabrication, optical communication, single molecule imaging, and so on. To date, it is still a challenge to realize nonlinear frequency conversion and manipulation of such vector beams because of the polarization sensitivity in most nonlinear processes. Here, for the first time, to the best of our knowledge, we generate second-harmonic vector beams by using three-wave mixing processes in our experiment, which occur in two orthogonally placed nonlinear crystals, and the vector property is recognized by using a Glan-Taylor polarizer. This nonlinear frequency conversion process enables vector beams to be obtained at new wavelengths, and opens up new possibilities for all-optical switching and manipulation of vector beams.
近年来，由于矢量光束在整个光束横截面上的迷人矢量特性，它们得到了广泛的研究，这对于光学微操控、光学微加工、光通信、单分子成像等领域非常有用。迄今为止，由于大多数非线性过程中的偏振灵敏度，实现这种矢量光束的非线性频率转换和操控仍然是一个挑战。在这里，据我们所知，我们首次在实验中通过三波混频过程产生了二次谐波矢量光束，该过程发生在两个正交放置的非线性晶体中，并且通过格兰泰勒偏振器识别出了矢量特性。这种非线性频率转换过程使得能够在新的波长获得矢量光束，并为全光开关和矢量光束的操控开辟了新的可能性。
