图 1  不同几何相位设计实现不同成像功能示意图。(a)在焦平面实现任意曲线成像；(b) 定性检测入射光偏振类型；(c) 定量检测线偏振光偏振方向，A为圆上的第j个点，AP为入射线偏振光的方向，AQ为点A处线偏振光的方向，AQ经过圆心

Figure 1.  Schematic diagram illustrating the realization of different imaging fuctions through various geometric phase designs. (a) Achieving arbitrary curve imaging on focal plane; (b) Qualitative detection of the polarization type of incident light; (c) Quantitative detection of the polarization direction of linearly polarized light, where A is the j-th point on the circle, AP is the direction of the incident linearly polarized light, AQ is the direction of the linearly polarized light at point A, and AQ passes through the center of the circle

图 2  超构表面单元结构及其透射率。(a) 超构表面单元结构；(b) 同极化圆偏振光(虚线)和交叉极化圆偏振光(实线)的透射率

Figure 2.  Metasurface unit cell structure and its transmittance. (a) The metasurface unit cell structure; (b) the transmittance of circularly co-polarized light (dashed line) and circularly cross-polarized light (solid line)

图 3  不同超构表面单元数下单个焦点的归一化强度图。(a) N=100; (b) N=250; (c) N=500; (d) N=1000

Figure 3.  Normalized intensity map of a single focal point under different numbers of metasurface unit cells. (a) N=100; (b) N=250; (c) N=500; (d) N=1000

图 4  不同形状曲线的光强分布。(a) 椭圆；(b) 圆；(c) 抛物线；(d) 三角形；(e) 正方形；(f) 字母“LZU”

Figure 4.  The intensity distribution of different curves. (a) an ellipse; (b) a circle; (c) a parabola; (d) a triangle; (e) a square; (f) the letters “LZU”

图 5  不同偏振入射光时其对应的图像。(a)左旋圆偏振光入射；(b) 左旋椭圆偏振光入射；(c) 线偏振光入射；(d) 右旋椭圆偏振光入射；(b) 右旋圆偏振光入射。左侧表示入射的偏振状态，右侧表示相应偏振态入射时焦平面处的图像

Figure 5.  Incident light with different polarizations and their corresponding images. (a) Incident of LCP light; (b) incident of left-handed elliptically polarized light; (c) incident of linear polarized light; (d) incident of right-handed elliptically polarized light; (e) incident of RCP light. The left denotes the incident polarized state and the right denotes corresponding images at the focal plane

图 6  测量偏振方向角原理图。入射偏振方向角为θ，极坐标方位角为φ。(a) θ=$ 0 $，(b) θ=$ \dfrac{\mathrm{{\text{π}} }}{4} $，(c) θ=$ \dfrac{\mathrm{{\text{π}} }}{6} $，(d) θ=$ \dfrac{3\mathrm{{\text{π}} }}{2} $

Figure 6.  Illustrates the schematic diagram for measuring the polarization rotation angle. The incident polarization angle is θ, with angular coordinates φ: (a) θ=$ 0 $, (b) θ=$ \dfrac{\mathrm{{\text{π}} }}{4} $, (c) θ=$ \dfrac{\mathrm{{\text{π}} }}{6} $, (d) θ=$ \dfrac{3\mathrm{{\text{π}} }}{2} $

图 7  光强随入射偏振方向角变化的图像及其归一化强度分布曲线。入射偏振光的旋转角度分别是(a) $ 0 $，(b) $ \dfrac{\mathrm{{\text{π}} }}{4} $，(c) $ \dfrac{\mathrm{{\text{π}} }}{2} $，(d) $ \dfrac{3\mathrm{{\text{π}} }}{4} $。图中第一行左侧箭头表示入射线偏振光的方向，右侧箭头表示焦平面前偏振片传输轴的方向

Figure 7.  Lignt intensity varies with the polar angle and their normalized intensity distribution curves. The rotation angles of incident polarized light are (a) $ 0 $, (b) $ \dfrac{\mathrm{{\text{π}} }}{4} $, (c) $ \dfrac{\mathrm{{\text{π}} }}{2} $, (d) $ \dfrac{3\mathrm{{\text{π}} }}{4} $, respectively. The left arrow in the first row shows the direction of incident polarized light, while the right arrow shows the direction of the transmission axis of the analyzer before the focal plane

图 8  不同情况下的光强随极角变化图像及其归一化强度分布曲线。(a) (d)理想情况；(b) (e)高斯噪声；(c) (f)大气弱湍流

Figure 8.  Images depicting the variation of the light intensity with polar angle under different conditions. (a) (d) The ideal circumstance. (c) (f) Include atmospheric turbulence. (b) (e) Include Gaussian noise

图 9  偏振方向角预设值和测量值对比曲线图

Figure 9.  Comparison between actual and measured values of polarization rotation angle