Launching and Manipulation of Higher‐Order In‐Plane Hyperbolic Phonon Polaritons in Low‐Dimensional Heterostructures
Launching and Manipulation of Higher‐Order In‐Plane Hyperbolic Phonon Polaritons in Low‐Dimensional Heterostructures
复制标题
低维异质结构中高阶平面双曲声子极化子的发射和操纵
DOI：
10.1002/adma.202300301
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发表时间：
2023
影响因子：
29.4
通讯作者：
Caldwell, Joshua D.
中科院分区：
文献类型：
--
作者：
Lu, Guanyu;Pan, Zhiliang;Gubbin, Christopher R.;Kowalski, Ryan A.;De Liberato, Simone;Li, Deyu;Caldwell, Joshua D.
通过红外（IR）光子与极性晶格振动耦合来激发双曲声子极化激元（HPhP）。这样的HPhP提供低损耗，高度受限的光传播在亚波长尺度与平面外或平面内双曲波前。对于HPhP，虽然双曲色散意味着在给定频率下具有波矢量分布的多个传播模式，但到目前为止，通过实验发射和探测提供更强波长压缩的高阶模式一直具有挑战性，特别是对于面内HPhP。在这项工作中，报告了在3C-SiC纳米线（NW）/α-MoO 3异质结构上激发的高阶面内HPhP模式的实验观察，其中利用极性NW的低维度和低损耗性质，2D α-MoO 3晶体内的高阶HPhP模式由1D 3C-SiC NW发射。进一步研究了发射机制，并确定了有效发射这种高阶模式的要求。此外，通过改变3C-SiC NW和α-MoO 3晶体之间的几何取向，证明了作为调谐方法的高阶HPhP色散的操纵。这项工作说明了一个极其各向异性的低维异质结构平台，用于在深亚波长尺度上限制和配置电磁波，用于一系列红外应用，包括传感，纳米成像和片上光子学。
Hyperbolic phonon polaritons (HPhPs) are stimulated by coupling infrared (IR) photons with the polar lattice vibrations. Such HPhPs offer low‐loss, highly confined light propagation at subwavelength scales with out‐of‐plane or in‐plane hyperbolic wavefronts. For HPhPs, while a hyperbolic dispersion implies multiple propagating modes with a distribution of wavevectors at a given frequency, so far it has been challenging to experimentally launch and probe the higher‐order modes that offer stronger wavelength compression, especially for in‐plane HPhPs. In this work, the experimental observation of higher‐order in‐plane HPhP modes stimulated on a 3C‐SiC nanowire (NW)/α‐MoO3heterostructure is reported where leveraging both the low‐dimensionality and low‐loss nature of the polar NWs, higher‐order HPhPs modes within 2D α‐MoO3crystal are launched by the 1D 3C‐SiC NW. The launching mechanism is further studied and the requirements for efficiently launching of such higher‐order modes are determined. In addition, by altering the geometric orientation between the 3C‐SiC NW and α‐MoO3crystal, the manipulation of higher‐order HPhP dispersions as a method of tuning is demonstrated. This work illustrates an extremely anisotropic low dimensional heterostructure platform to confine and configure electromagnetic waves at the deep‐subwavelength scales for a range of IR applications including sensing, nano‐imaging, and on‐chip photonics.