Structuring Nonlinear Wavefront Emitted from Monolayer Transition-Metal Dichalcogenides
Structuring Nonlinear Wavefront Emitted from Monolayer Transition-Metal Dichalcogenides
复制标题
构造单层过渡金属二硫属化物发射的非线性波前
DOI：
10.34133/2020/9085782
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发表时间：
2020-04-05
期刊：
影响因子：
11
通讯作者：
Lu, Peixiang
中科院分区：
文献类型：
--
作者：
Hong, Xuanmiao;Hu, Guangwei;Lu, Peixiang
对定制非线性的需求不断增长，需要一种具有异常相位不连续性的结构，以实现非线性光学手性、全息成像和非线性波前控制。过渡金属二硫属化物（TMDC）单层在几埃厚度内提供巨大的光学非线性，但光学吸收和域尺寸的限制对使用经典光源的非线性发射的波前控制施加了限制。相比之下，基于贵金属的等离子体纳米筛支持巨大的场增强和精确的非线性相位控制，具有百纳米像素级分辨率；然而，它们本质上具有较弱的非线性敏感性。在这里，我们通过将 TMDC 单层与等离子体纳米筛集成来报告一种多功能非线性界面，产生两种成分都无法访问的截然不同的非线性功能。这种混合非线性接口允许产生二次谐波 (SH) 轨道角动量 (OAM)、光束控制、多功能偏振控制和全息图，有效 SH 非线性 χ(2) 约为 25nm/V。该设计平台协同 TMDC 单层和等离子体纳米筛，实现可调谐几何相位和大场增强，为多功能和超紧凑非线性光学器件铺平了道路。
The growing demand for tailored nonlinearity calls for a structure with unusual phase discontinuity that allows the realization of nonlinear optical chirality, holographic imaging, and nonlinear wavefront control. Transition-metal dichalcogenide (TMDC) monolayers offer giant optical nonlinearity within a few-angstrom thickness, but limitations in optical absorption and domain size impose restriction on wavefront control of nonlinear emissions using classical light sources. In contrast, noble metal-based plasmonic nanosieves support giant field enhancements and precise nonlinear phase control, with hundred-nanometer pixel-level resolution; however, they suffer from intrinsically weak nonlinear susceptibility. Here, we report a multifunctional nonlinear interface by integrating TMDC monolayers with plasmonic nanosieves, yielding drastically different nonlinear functionalities that cannot be accessed by either constituent. Such a hybrid nonlinear interface allows second-harmonic (SH) orbital angular momentum (OAM) generation, beam steering, versatile polarization control, and holograms, with an effective SH nonlinearity χ(2) of ~25 nm/V. This designer platform synergizes the TMDC monolayer and plasmonic nanosieves to empower tunable geometric phases and large field enhancement, paving the way toward multifunctional and ultracompact nonlinear optical devices.