Chen Cong, Mi Jiajia, Chen Panpan, Du Xiang, Xi Jianxin, Liang Li, Shi Jianping
College of Physics and Electronic Technology, Anhui Normal University, Wuhu 241000, China.
Anhui Province Key Laboratory of Photo-Electronic Materials Science and Technology, Wuhu 241000, China.
Materials (Basel). 2021 Jan 10;14(2):326. doi: 10.3390/ma14020326.
With the rapid development of on-chip optics, integrated optical devices with better performance are desirable. Waveguide couplers are the typical integrated optical devices, allowing for the fast transmission and conversion of optical signals in a broad working band. However, traditional waveguide couplers are limited by the narrow operation band to couple the spatial light into the chip and the fixed unidirectional transmission of light flow. Furthermore, most of the couplers only realize unidirectional transmission under the illumination of the linear polarized light. In this work, a broadband polarization directional coupler based on a metallic catenary antenna integrated on a silicon-on-insulator (SOI) waveguide has been designed and demonstrated under the illumination of the circularly polarized light. By applying the genetic algorithm to optimize the multiple widths of the metallic catenary antenna, the numerical simulation results show that the extinction ratio of the coupler can be maintained larger than 18 dB in a wide operation band of 300 nm (from 1400 to 1700 nm). Moreover, the coupler can couple the spatial beam into the plane and transmit in the opposite direction by modulating the rotation direction of the incident light. The broadband polarization directional coupler might have great potential in integrated optoelectronic devices and on-chip optical devices.
随着片上光学的快速发展，人们期望获得性能更优的集成光学器件。波导耦合器是典型的集成光学器件，可在较宽的工作频段内实现光信号的快速传输与转换。然而，传统波导耦合器存在局限，其将空间光耦合进芯片的工作频段较窄，且光流的传输方向固定为单向。此外，大多数耦合器仅在线偏振光照射下实现单向传输。在这项工作中，基于集成在绝缘体上硅（SOI）波导上的金属悬链天线，设计并展示了一种宽带偏振定向耦合器，该耦合器在圆偏振光照射下工作。通过应用遗传算法优化金属悬链天线的多个宽度，数值模拟结果表明，在300 nm的宽工作频段（从1400至1700 nm）内，耦合器的消光比可保持大于18 dB。此外，通过调制入射光的旋转方向，该耦合器可将空间光束耦合进平面并沿相反方向传输。这种宽带偏振定向耦合器在集成光电器件和片上光学器件中可能具有巨大潜力。
