Yang Jiong, Krix Zeb E, Kim Sejeong, Tang Jianbo, Mayyas Mohannad, Wang Yifang, Watanabe Kenji, Taniguchi Takashi, Li Lu Hua, Hamilton Alex R, Aharonovich Igor, Sushkov Oleg P, Kalantar-Zadeh Kourosh
School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia.
Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies, University of New South Wales (UNSW), Sydney, NSW 2052, Australia.
ACS Nano. 2021 May 25;15(5):9134-9142. doi: 10.1021/acsnano.1c02507. Epub 2021 Apr 30.
Phonon-polaritons (PhPs) arise from the strong coupling of photons to optical phonons. They offer light confinement and harnessing below the diffraction limit for applications including sensing, imaging, superlensing, and photonics-based communications. However, structures consisting of both suspended and supported hyperbolic materials on periodic dielectric substrates are yet to be explored. Here we investigate phonon-polaritonic crystals (PPCs) that incorporate hyperbolic hexagonal boron nitride (hBN) to a silicon-based photonic crystal. By using the near-field excitation in scattering-type scanning near-field optical microscopy (s-SNOM), we resolved two types of repetitive local field distribution patterns resembling the Archimedean-like tiling on hBN-based PPCs, , dipolar-like field distributions and highly dispersive PhP interference patterns. We demonstrate the tunability of PPC band structures by varying the thickness of hyperbolic materials, supported by numerical simulations. Lastly, we conducted scattering-type nanoIR spectroscopy to confirm the interaction of hBN with photonic crystals. The introduced PPCs will provide the base for fabricating essential subdiffraction components of advanced optical systems in the mid-IR range.
声子极化激元（PhPs）源于光子与光学声子的强耦合。它们在传感、成像、超透镜和基于光子学的通信等应用中，能实现低于衍射极限的光限制与利用。然而，由周期性介电基片上的悬浮和支撑双曲材料组成的结构尚未得到探索。在此，我们研究了将双曲六方氮化硼（hBN）并入硅基光子晶体的声子极化激元晶体（PPCs）。通过在散射型扫描近场光学显微镜（s-SNOM）中使用近场激发，我们解析出两种类似阿基米德镶嵌的重复局部场分布模式，即基于hBN的PPCs上的偶极子样场分布和高度色散的PhP干涉模式。通过数值模拟的支持，我们证明了通过改变双曲材料的厚度可实现PPC能带结构的可调谐性。最后，我们进行了散射型纳米红外光谱分析，以确认hBN与光子晶体的相互作用。引入的PPCs将为制造中红外范围内先进光学系统的基本亚衍射组件提供基础。
