Oh Jaewon, Li Kangmei, Yang Jun, Chen Wei Ting, Li Ming-Jun, Dainese Paulo, Capasso Federico
Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
Corning Inc., Painted Post, New York 14870, United States.
ACS Photonics. 2022 Mar 16;9(3):929-937. doi: 10.1021/acsphotonics.1c01744. Epub 2022 Mar 7.
Optical fiber communications rely on multiplexing techniques that encode information onto various degrees of freedom of light to increase the transmission capacity of a fiber. However, the rising demand for larger data capacity is driving the need for a multiplexer for the spatial dimension of light. We introduce a mode-division multiplexer and demultiplexer design based on a metasurface cavity. This device performs, on a single surface, mode conversion and coupling to fibers without any additional optics. Converted modes have high fidelity due to the repeated interaction of light with the metasurface's phase profile that was optimized using an inverse design technique known as adjoint analysis. We experimentally demonstrate a compact and highly integrated metasurface-based mode multiplexer that takes three single-mode fiber inputs and converts them into the first three linearly polarized spatial modes of a few-mode fiber with fidelities of up to 72% in the C-band (1530-1565 nm).
光纤通信依赖于复用技术，这些技术将信息编码到光的各种自由度上，以增加光纤的传输容量。然而，对更大数据容量的需求不断增长，促使人们需要一种用于光的空间维度的复用器。我们介绍了一种基于超表面腔的模式分复用器和解复用器设计。该器件在单个表面上执行模式转换并耦合到光纤，无需任何额外的光学元件。由于光与超表面相位分布的重复相互作用，转换后的模式具有高保真度，该相位分布是使用一种称为伴随分析的逆设计技术进行优化的。我们通过实验展示了一种基于超表面的紧凑型高度集成模式复用器，它接收三个单模光纤输入，并将它们转换为少模光纤的前三个线性偏振空间模式，在C波段（1530 - 1565纳米）的保真度高达72%。
