Deng Lin, Cai Ziqiang, Liu Yongmin
Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115, United States.
Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States.
Nano Lett. 2024 Jul 24;24(29):9042-9049. doi: 10.1021/acs.nanolett.4c02231. Epub 2024 Jul 15.
On-chip metasurfaces play a crucial role in bridging the guided mode and free-space light, enabling full control over the wavefront of scattered free-space light in an optimally compact manner. Recently, researchers have introduced various methods and on-chip metasurfaces to engineer the radiation of guided modes, but the total functions that a single metasurface can achieve are still relatively limited. In this work, we propose a novel on-chip metasurface design that can multiplex up to four distinct functions. We can efficiently control the polarization state, phase, angular momentum, and beam profile of the radiated waves by tailoring the geometry of V-shaped nanoantennas integrated on a slab waveguide. We demonstrate several innovative on-chip metasurfaces for switchable focusing/defocusing and for multifunctional generators of orbital angular momentum beams. Our on-chip metasurface design is expected to advance modern integrated photonics, offering applications in optical data storage, optical interconnection, augmented reality, and virtual reality.
片上超表面在连接导模和自由空间光方面起着至关重要的作用，能够以最佳紧凑的方式对散射自由空间光的波前进行全面控制。最近，研究人员已经引入了各种方法和片上超表面来设计导模的辐射，但单个超表面能够实现的总功能仍然相对有限。在这项工作中，我们提出了一种新颖的片上超表面设计，它可以复用多达四种不同的功能。通过定制集成在平板波导上的V形纳米天线的几何形状，我们可以有效地控制辐射波的偏振态、相位、角动量和光束轮廓。我们展示了几种用于可切换聚焦/散焦以及用于轨道角动量光束多功能发生器的创新型片上超表面。我们的片上超表面设计有望推动现代集成光子学的发展，在光学数据存储、光互连、增强现实和虚拟现实等领域提供应用。
