Zhang Tao, Liu Jiachen, Gu Liangliang, Hu Haifeng, Zhan Qiwen
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
Zhangjiang Laboratory, 100 Haike Road, Shanghai, 201204, China.
Sci Rep. 2025 Jan 2;15(1):128. doi: 10.1038/s41598-024-84587-7.
In recent years, research on chiral bound states in the continuum (BIC) has surged, leading to the development of various chiral metasurfaces with narrow bandwidths by breaking of in-plane and out-of-plane symmetries. However, the ability to dynamically tune the working band remains relatively unexplored, which is valuable for chiral sensing applications. Optical phase-change materials, with tunable dielectric constants and switchable properties during phase transition, offer the potential for dynamic control of optical metasurfaces. This work demonstrates a wavelength-tunable infrared chiral metasurface by combining the phase-change material GST with chiral BIC structures. By varying the longitudinal tilt angle of the nanostructure, an infrared chiral metasurface with an extremely narrow bandwidth of chiral resonance and a CD value of over 0.8 is designed. The phase-change properties of GST enable wavelength-tunable chiral resonance without altering the structural parameters, and the influence of key structural parameters of the metasurface on the chiral resonance wavelength and CD value is analyzed. The proposed chiral BIC metasurface with phase-change materials shows promising application prospects in filter devices, chiral thermal switches, infrared imaging, and tunable chiral photonics.
近年来，对连续统中的手性束缚态（BIC）的研究激增，通过打破面内和面外对称性，导致了各种具有窄带宽的手性超表面的发展。然而，动态调谐工作频段的能力仍相对未被探索，这对手性传感应用很有价值。光学相变材料在相变过程中具有可调介电常数和可切换特性，为光学超表面的动态控制提供了潜力。这项工作通过将相变材料GST与手性BIC结构相结合，展示了一种波长可调的红外手性超表面。通过改变纳米结构的纵向倾斜角度，设计了一种具有极窄手性共振带宽和超过0.8的圆二色性（CD）值的红外手性超表面。GST的相变特性能够在不改变结构参数的情况下实现波长可调的手性共振，并分析了超表面关键结构参数对手性共振波长和CD值的影响。所提出的具有相变材料的手性BIC超表面在滤波器件、手性热开关、红外成像和可调谐手性光子学方面显示出广阔的应用前景。
