Zhang Di, He Changhui, Zhu Zhenbo, Yu Fangli, Chen Qiang, Hu Jiabei, Huang Min
Opt Express. 2024 Apr 22;32(9):16075-16082. doi: 10.1364/OE.522316.
Phase modulated metasurface (PMM) can control the transmission state of electromagnetic (EM) wave through phase modulation scheme on the interface. Orbital angular momentum (OAM) vortex wave is denoted by the helical phase distribution of the wave front. The interaction between OAM vortex wave and PMM is investigated in this paper. The mathematical model is firstly established according to the array theory. Whereafter, two typical PMMs of chessboard metasurface (CBM) and phase gradient metasurface (PGM) are exploited as examples to uncover the scattering characteristics under illumination of OAM vortex wave. For CBM, the phase cancellation scheme is found to be broken when the OAM order l equals to ±2 under both normal incidence and oblique incidence. It reveals that the OAM vortex wave is a promising approach for metasurface stealth target detection. For PGM, the scattered wave still keeps the OAM feature but is deflected to the non-specular direction, which reveals that the generalized Snell's law is also suitable to OAM vortex wave. The discoveries of this paper may find applications in radar detection fields using OAM vortex wave.
相位调制超表面（PMM）可以通过界面上的相位调制方案来控制电磁波（EM）的传输状态。轨道角动量（OAM）涡旋波由波前的螺旋相位分布表示。本文研究了OAM涡旋波与PMM之间的相互作用。首先根据阵列理论建立了数学模型。此后，以棋盘超表面（CBM）和相位梯度超表面（PGM）这两种典型的PMM为例，揭示了在OAM涡旋波照射下的散射特性。对于CBM，发现当OAM阶数l等于±2时，在垂直入射和斜入射情况下，相位抵消方案都会失效。这表明OAM涡旋波是超表面隐身目标检测的一种有前途的方法。对于PGM，散射波仍保持OAM特征，但会偏转到非镜面方向，这表明广义斯涅尔定律也适用于OAM涡旋波。本文的发现可能会在使用OAM涡旋波的雷达探测领域找到应用。
