Active control of anapole states by structuring the phase-change alloy Ge2Sb2Te5

• DOI: 10.1038/s41467-018-08057-1
• Publication Date: 2019-01-23T11:32:59Z
• Authors: Jingyi Tian; Hao Luo; Yuanqing Yang; Fei Ding; Yurui Qu; Ding Zhao; Min Qiu; Sergey I. Bozhevo...
• Keywords: Nanophotonics

High-index dielectric nanoparticles supporting a distinct series of Mie resonances have enabled new class optical antennas with unprecedented functionalities. The great wealth multipolar responses has not only brought in physical insight but also spurred practical applications. However, how to make such colorful resonance palette actively tunable is still elusive. Here, we demonstrate that the structured phase-change alloy Ge2Sb2Te5 (GST) can support diverse set active tunability. By harnessing dramatic contrast GST, realize broadband (Δλ/λ ~ 15%) mode shifting between an electric dipole and anapole state. Active control higher-order anapoles multimodal tuning are investigated, which GST serve as multispectral switch high extinction contrasts (>6 dB). With all these findings, our study provides direction for realizing nanophotonic devices.