Department of Physics, Institute for Advanced Studies in Basic Sciences, 45195-1159, Zanjan, Iran.
Dipartimento di Ingegneria dell'Informazione, Università di Padova, I-35131, Padova, Italy.
Sci Rep. 2017 Jun 19;7(1):3835. doi: 10.1038/s41598-017-04118-5.
Recent studies demonstrated that the optical channels encoded by Orbital Angular Momentum (OAM) are capable candidates for improving the next generation of communication systems. OAM states can enhance the capacity and security of high-dimensional communication channels in both classical and quantum regimes based on optical fibre and free space. Hence, fast and precise control of the beams encoded by OAM can provide their commercial applications in the compatible communication networks. Integrated optical devices are good miniaturized options to perform this issue. This paper proposes a numerically verified integrated high-frequency electro-optical modulator for manipulation of the guided modes encoded in both OAM and polarization states. The proposed modulator is designed as an electro-optically active Lithium Niobate (LN) core photonic wire with silica as its cladding in a LN on Insulator (LNOI) configuration. It consists of two successive parts; a phase shifter to reverse the rotation handedness of the input OAM state and a polarization converter to change the horizontally polarized OAM state to the vertically polarized one. It is shown that all four possible output polarization-OAM encoded states can be achieved with only 6 V and 7 V applied voltages to the electrodes in the two parts of the modulator.
最近的研究表明，轨道角动量 (OAM) 编码的光通道是改善下一代通信系统的有潜力的候选者。OAM 态基于光纤和自由空间，在经典和量子领域都可以提高高维通信信道的容量和安全性。因此，对 OAM 编码光束的快速和精确控制可以为兼容通信网络中的它们的商业应用提供支持。集成光学器件是实现这一问题的很好的小型化选择。本文提出了一种数值验证的集成高频电光调制器，用于操纵 OAM 和偏振态编码的导模。所提出的调制器设计为具有电光活性的铌酸锂 (LN) 芯光子线，其包层为 LN 上的绝缘体 (LNOI) 结构中的二氧化硅。它由两个连续的部分组成; 一个相移器用于反转输入 OAM 态的旋转手性，一个偏振转换器用于将水平偏振的 OAM 态转换为垂直偏振的 OAM 态。结果表明，通过在调制器的两个部分中的电极施加 6V 和 7V 的电压，可以实现所有四种可能的输出偏振-OAM 编码状态。
