Active dielectric metasurface based on phase-change medium

详细信息    查看全文

• 作者：Cheng Hung Chu ; Ming Lun Tseng ; Jie Chen ; Pin Chieh Wu ; Yi-Hao Chen ; Hsiang-Chu Wang ; Ting-Yu Chen ; Wen Ting Hsieh ; Hui Jun Wu ; Greg Sun and Din Ping Tsai
• 刊名：Laser & Photonics Reviews
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：10
• 期：6
• 页码：986-994
• 全文大小：1643K
• ISSN：1863-8899

文摘

We propose all-dielectric metasurfaces that can be actively re-configured using the phase-change material Ge₂Sb₂Te₅ (GST) alloy. With selectively controlled phase transitions on the composing GST elements, metasurfaces can be tailored to exhibit varied functionalities. Using phase-change GST rod as the basic building block, we have modelled metamolecules with tunable optical response when phase change occurs on select constituent GST rods. Tunable gradient metasurfaces can be realized with variable supercell period consisting of different patterns of the GST rods in their amorphous and crystalline states. Simulation results indicate a range of functions can be delivered, including multilevel signal modulating, near-field coupling of GST rods, and anomalous reflection angle controlling. This work opens up a new space in exploring active meta-devices with broader applications that cannot be achieved in their passive counterparts with permanent properties once fabricated.