Wang Yue, Wang Yu, Yang Guohui, Li Qingyan, Zhang Yu, Yan Shiyu, Wang Chunhui
National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001, China.
Shenzhen Glint Institute of AI and Robotics, Shenzhen 518057, China.
Nanomaterials (Basel). 2021 Jun 11;11(6):1552. doi: 10.3390/nano11061552.
Optical phased arrays (OPAs) are essential optical elements in applications that require the ability to manipulate the light-wavefront, such as beam focusing and light steering. To miniaturize the optical components, active metasurfaces, especially graphene metasurfaces, are used as competent alternatives. However, the metasurface cannot achieve strong resonance effect and phase control function in the mid-infrared region only relying on a single-layer graphene. Here we present a graphene-metal hybrid metasurface that can generate a specific phase or a continuous sweep in the range of a 275°-based single-layer graphene structure. A key feature of our design is that the phase adjustment mainly depends on the combination mechanism of resonance intensity and frequency modulation. An all-solid-state, electrically tunable, and reflective OPA is designed by applying the bias voltage to a different pixel metasurface. The simulation results show that the maximum deflection angle of the OPA can reach 42.716°, and the angular resolution can reach 0.62°. This design can be widely applied to mid-infrared imaging, optical sensing, and optical communication systems.
光学相控阵（OPAs）是需要具备操纵光波前能力的应用中的关键光学元件，例如光束聚焦和光转向。为了使光学元件小型化，有源超表面，尤其是石墨烯超表面，被用作有效的替代方案。然而，仅依靠单层石墨烯，超表面在中红外区域无法实现强共振效应和相位控制功能。在此，我们展示了一种石墨烯-金属混合超表面，它可以在基于275°的单层石墨烯结构范围内产生特定相位或连续扫描。我们设计的一个关键特性是相位调整主要取决于共振强度和频率调制的组合机制。通过向不同像素超表面施加偏置电压，设计了一种全固态、电可调且反射式的OPA。仿真结果表明，OPA的最大偏转角可达42.716°，角分辨率可达0.62°。这种设计可广泛应用于中红外成像、光学传感和光通信系统。
