Nonlinear intersubband polaritonic metasurfaces, which integrate giant nonlinear responses derived from intersubband transitions of multiple quantum wells (MQWs) with plasmonic nanoresonators, not only facilitate efficient frequency conversion at pump intensities on the order of few tens of kW cm^-2 but also enable electrical modulation of nonlinear responses at the individual meta-atom level and dynamic beam manipulation. The electrical modulation characteristics of the magnitude and phase of the nonlinear optical response are realized through Stark tuning of the resonant intersubband nonlinearity. In this study, we report, for the first time, experimental implementations of electrical modulation characteristics of mid-infrared third-harmonic generation (THG) using an intersubband polaritonic metasurface based on MQW with electrically tunable third-order nonlinear response. Experimentally, we achieved a 450% modulation depth of the THG signal, 86% suppression of zero-order THG diffraction tuning based on local phase tuning exceeding 180 degrees, and THG beam steering using phase gradients. Our work proposes a new route for electrically tunable flat nonlinear optical elements with versatile functionalities.

非线性子带间极化超表面将多量子阱（MQW）子带间跃迁产生的巨大非线性响应与等离子体纳米谐振器集成在一起，不仅有助于在几十kW cm ^-2量级的泵浦强度下进行高效频率转换，而且还能够实现电调制单个元原子水平的非线性响应和动态光束操纵。非线性光学响应的​​幅度和相位的电调制特性是通过谐振子带间非线性的斯塔克调谐来实现的。在这项研究中，我们首次报告了使用基于 MQW 的子带间极化超表面（具有电可调三阶非线性响应）来实验实现中红外三次谐波产生 (THG) 的电调制特性。实验上，我们实现了 THG 信号的 450% 调制深度、基于超过 180 度的局部相位调谐的零阶 THG 衍射调谐抑制 86%，以及使用相位梯度的 THG 光束控制。我们的工作提出了一种具有多功能的电可调平面非线性光学元件的新途径。