Wang Kuidong, Liu Ai-Yin, Hsiao Hui-Hsin, Genet Cyriaque, Ebbesen Thomas
CNRS, ISIS, & icFRC, University of Strasbourg, 8 allée Gaspard Monge, Strasbourg 67000, France.
Institute of Electro-Optical Engineering, National Taiwan Normal University, Taipei 11677, Taiwan.
Nano Lett. 2022 Jan 26;22(2):702-709. doi: 10.1021/acs.nanolett.1c03876. Epub 2022 Jan 7.
Strong coupling provides a powerful way to modify the nonlinear optical properties of materials. The coupling strength of the state-of-the-art strongly coupled systems is restricted by a weak-field confinement of the cavity, which limits the enhancement of the optical nonlinearity. Here, we investigate a strong coupling between Mie resonant modes of high-index dielectric nanocavities and an epsilon-near-zero mode of an ultrathin indium tin oxide film and obtain an anticrossing splitting of 220 meV. Static nonlinear optical measurements reveal a large enhancement in the intensity-independent effective optical nonlinear coefficients, reaching more than 3 orders of magnitude at the coupled resonance. In addition, we observe a transient response of ∼300 fs for the coupled system. The ultrafast and large optical nonlinear coefficients presented here offer a new route towards strong coupling-assisted high-speed photonics.
强耦合为改变材料的非线性光学性质提供了一种强有力的方法。当前最先进的强耦合系统的耦合强度受到腔的弱场限制，这限制了光学非线性的增强。在此，我们研究了高折射率介电纳米腔的米氏共振模式与超薄氧化铟锡薄膜的近零介电常数模式之间的强耦合，并获得了220毫电子伏特的反交叉分裂。静态非线性光学测量表明，与强度无关的有效光学非线性系数大幅增强，在耦合共振时达到超过3个数量级。此外，我们观察到耦合系统的瞬态响应约为300飞秒。这里呈现的超快且大的光学非线性系数为强耦合辅助高速光子学提供了一条新途径。
