近日，中国科学院福建物质结构研究所的罗军华&赵三根与华中科技大学的谷洪刚等人合作并取得一项新进展。经过不懈努力，他们发现一种用于有效操纵光偏振的具有巨大光学各向异性的可溶液加工天然晶体。相关研究成果已于2024年6月14日在国际知名学术期刊《自然—光子学》上发表。
该研究团队成功展示了一种可通过溶液加工的天然晶体C3H8N6I6·3H2O，在可见光至红外光谱区域内，其双折射系数高达2.8，表现出极为显著的双折射特性。通过结合临界点分析和第一性原理计算，研究人员发现，这种显著的光学各向异性主要源于晶体中平行排列的线性(I3) -结构单元，这种结构使得不同晶体轴上的偏振率差异达到最大化。
这一发现凸显了天然多碘化物晶体作为一个卓越平台的巨大潜力，能够满足光通信、三维成像、超高分辨率传感等领域中对偏振光子应用日益增长的需求。
据悉，光学各向异性是一种空间不对称的光-物质相互作用，表现为双折射和二色性，在现代光学中对光偏振的控制至关重要。到目前为止，各种天然双折射晶体被广泛使用，但它们的双折射限制在<0.3。
附：英文原文
Title: A solution-processable natural crystal with giant optical anisotropy for efficient manipulation of light polarization
Author: Zhou, Yang, Guo, Zhengfeng, Gu, Honggang, Li, Yanqiang, Song, Yipeng, Liu, Shiyuan, Hong, Maochun, Zhao, Sangen, Luo, Junhua
Issue&Volume: 2024-06-14
Abstract: Optical anisotropy, a spatially asymmetric light–matter interaction that manifests itself as birefringence and dichroism, is paramount for manipulating light polarization in modern optics. So far, various natural birefringent crystals are widely used, but their birefringence is limited to <0.3. Here we demonstrate a solution-processable natural crystal C3H8N6I6·3H2O with giant birefringence up to 2.8 within the visible to infrared spectral region. Combining critical point analysis and the first-principles calculations, we reveal that this giant optical anisotropy mainly comes from the linear (I3) -structural units in a parallel arrangement, which maximizes the difference of polarizability along the different crystallographic axes. This work highlights the potential of natural polyiodide crystals as an outstanding platform to satisfy the increasing demand for photonic applications that exploit polarization in optical communication, three-dimensional imaging, ultrahigh-resolution sensing and other tasks.
DOI: 10.1038/s41566-024-01461-8
Source: https://www.nature.com/articles/s41566-024-01461-8