Tunable waveguide mode of hyperbolic phonon polaritons in α-MoO_(3) flake/gold slit composite structure  

作　　者：NAN DENG ZHONGAO HUANG KAI WANG KUN WANG XIAOBO HAN XINYING ZHANG BING WANG HUA LONG PEIXIANG LU 

机构地区：[1]Wuhan National Laboratory for Optoelectronics and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China [2]School of Electronic and Information Engineering,Hubei University of Science and Technology,Xianning 437100,China [3]Hubei Key Laboratory of Optical Information and Pattern Recognition,Wuhan Institute of Technology,Wuhan 430205,China

出　　处：《Photonics Research》2024年第12期2901-2911,共11页光子学研究(英文版)

基　　金：National Natural Science Foundation of China(12274157,12021004,12274334,11904271);National Key Research and Development Program of China(2022YFA1604403);Natural Science Foundation of Hubei Province of China(2023AFA076).

摘　　要：Hyperbolic phonon polaritons(HPhPs)in van der Waals layered polar crystals exhibit extreme light confinement capability,providing an unprecedented research opportunity to manipulate nanoscale midinfrared photons.Precise tuning of HPhPs propagation characteristics and near-field energy routing is crucial for applying polaritonic devices.Here,we demonstrate a widely tunable waveguide mode of HPhPs in an α-MoO_(3) flake/gold slit composite structure.By varying the width of the gold slit from 3μm to 220 nm,the compression ratio of HPhPs wavelength relative to the incident light wavelength can be adjusted from 35% to 8.6%,respectively.This is attributed to the introduction of the gold slit,which can effectively excite and guide HPhPs within an α-MoO_(3) flake,forming a confined waveguide mode.Notably,the excitation efficiency of HPhPs in the nanoscale ultranarrow waveguide can be enhanced by integrating an extended port at the waveguide port.In addition,the routing of polaritons in a Y-shaped waveguide is realized by modulating the frequency of the incident light.This work presents a promising platform for manipulating deep subwavelength polaritons in planar photonic devices for infrared applications.

关 键 词：waveguide tuning mode 

分 类 号：O482.3[理学—固体物理]