Abstract：
Integration of 2D semiconductors with photonic crystal slabs provides an attractive approach to achieving strong light-matter coupling and exciton-polariton formation in a chip-compatible geometry. However, for the development of practical devices, it is crucial that polariton excitations are easily tunable and exhibit a strong nonlinear response. Here we study neutral and charged exciton-polaritons in an electrostatically gated photonic crystal slab with an embedded monolayer semiconductor MoSe2 and experimentally demonstrate a novel approach to optical control based on polariton nonlinearity. We show that spatial modulation of the dielectric environment within the photonic crystal unit cell results in the formation of two distinct excitonic species with significantly different nonlinear responses of the corresponding charged exciton-polaritons under optical pumping. This behavior enables optical switching with ultrashort laser pulses and can be sensitively controlled via an electrostatic gate voltage. Our results open new avenues toward the development of active polaritonic devices in a compact chip-compatible implementation.
摘要：
2D半导体与光子晶体平板的集成提供了一种有吸引力的方法，可以在芯片兼容的几何结构中实现强光-物质耦合和激子-极化子形成。然而,为了开发实用的设备，至关重要的是，极化子激发易于调谐并表现出强非线性响应。在这里，我们研究了具有嵌入式单层半导体MoSe2的静电门控光子晶体板中的中性和带电激子-极化子，并通过实验证明了一种基于极化子非线性的光学控制新方法。我们表明，光子晶体晶胞内的介电环境的空间调制导致形成两种不同的激子物质，在光泵浦下，相应的带电激子-极化子的非线性响应显着不同。这种行为使得能够利用超短激光脉冲进行光学切换,并且可以通过静电栅极电压进行灵敏控制。我们的结果为在紧凑的芯片兼容实现中开发有源极化器件开辟了新的途径。
