Zhang Houjiao, Liu Ye, Liu Zhengqi, Liu Xiaoshan, Liu Guiqiang, Fu Guolan, Wang Junqiao, Shen Yun
Opt Express. 2021 Jan 4;29(1):70-81. doi: 10.1364/OE.412925.
In this work, we present an efficient polarization conversion device via using a hollow graphene metasurface. The platform can simultaneously realize a series of excellent performances, including the broadband x-to-y cross polarization conversion (CPC) function with near unity polarization conversion ratio (PCR), dual-frequency linear-to-circular polarization conversion (LTC-PC) function, and highly sensitive polarization conversion function manipulation under wide oblique incidence angle range. For instance, the proposed device obtains an x-to-y CPC function with the bandwidth up to 1.83 THz (χPCR ≥98.8%). Moreover, the x-to-y CPC function can be switched to LTC-PC function via artificially tuning the Fermi energy of graphene. The maximal frequency shift sensitivity (S) of polarization conversion function reaches 23.09 THz/eV, suggesting a frequency shift of 2.309 THz for the LTC-PC function when the chemical potential is changed by 0.1 eV. Based on these superior performances, the polarization converter can hold potential applications in integrated and compact devices, such as polarization sensor, switches and other optical polarization control components.
在这项工作中，我们展示了一种通过使用中空石墨烯超表面实现的高效偏振转换器件。该平台能够同时实现一系列优异性能，包括具有近乎单位偏振转换率（PCR）的宽带x到y交叉偏振转换（CPC）功能、双频线到圆偏振转换（LTC - PC）功能，以及在宽斜入射角范围内对偏振转换功能的高度灵敏操控。例如，所提出的器件实现了带宽高达1.83太赫兹的x到y CPC功能（χPCR≥98.8%）。此外，通过人工调节石墨烯的费米能，x到y CPC功能可以切换为LTC - PC功能。偏振转换功能的最大频移灵敏度（S）达到23.09太赫兹/电子伏特，这意味着当化学势改变0.1电子伏特时，LTC - PC功能的频移为2.309太赫兹。基于这些优异性能，该偏振转换器在集成和紧凑型器件中具有潜在应用，如偏振传感器、开关及其他光偏振控制组件。
