【作者】 陈浩； 郝晶晶； 张柏富； 许吉； 丁剑平；

【机构】 南京大学物理学院；

【摘要】 迄今为止,人们已对具有空间非均匀偏振分布的矢量光束和具有螺旋位相分布的涡旋光束已经被广泛研究。我们提出了一种利用空间光调制器(SLM)产生空间变化的矢量光束的方法,获得了一种具有空间位相和偏振分布各自被独立调控的矢量光束。我们在SLM上加载一个二维的全息光栅,该光栅位于一个4f系统的输入平面上。准直的入射光经SLM反射进入4f系统,在傅里叶频谱面上让x,y轴上的+1级衍射光分别通过两个正交的四分之一波片,在第二个透镜的后焦面上用一个与x轴夹角为45°的位相型Ronchi光栅将携带不同位相分布的左旋右旋圆偏振光合成(图1)。输出光束的位相和偏振分布可以通过空间光调制器上加载的二维全息光栅沿两个正交方向(x和y方向)携带的两种位相分布的分别独立调控。实验结果验证了该方法的有效性和自由调控的能力(图2)。这种新方法为我们研究矢量场和自旋轨道相互作用的新效应带来了方便。更多还原

【Abstract】 Until now,space-variant polarization vector beam and optical vortex with helical phase have been researched in a variety of realms.We proposed an approach to generating arbitrary space-variant vector beam with structured state of polarization(SOP) and phase distributions.A two-dimensional holographic grating is displayed on a spatial light modulator(SLM),At the Fourier plane of the 4-f system only two of first-orders loc ated respectively in the x and y axes are al lowed to pass through a spatial filter,and then converted by two λ/4 plates into the left-and right-hand circularly polarized beams,respectively.The selected orders are recombined by the second lens in its rear focal plane,in which a Ronchi phase grating is placed by 45°with respect to the x direction.The phase and the state of polarization of vector beams can be tailored arbitrarily,independently and dynamically,by a SLM.Optical experiments have validated the flexibility and capability of our method in vector beam engineering.The realization of the beams with controllable phase and SOP is expected to help us further e xplore the vector optical field and new effect of spin-orbital interaction.更多还原