Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK.
Department of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK.
Adv Mater. 2019 Jan;31(1):e1804801. doi: 10.1002/adma.201804801. Epub 2018 Nov 6.
Electrostriction is a property of all naturally occurring dielectrics whereby they are mechanically deformed under the application of an electric field. It is demonstrated here that an artificial metamaterial nanostructure comprising arrays of dielectric nanowires, made of silicon and indium tin oxide, is reversibly structurally deformed under the application of an electric field, and that this reconfiguration is accompanied by substantial changes in optical transmission and reflection, thus providing a strong electro-optic effect. Such metamaterials can be used as the functional elements of electro-optic modulators in the visible to near-infrared part of the spectrum. A modulator operating at 1550 nm with effective electrostriction and electro-optic coefficients of order 10 m V and 10 m V , respectively, is demonstrated. Transmission changes of up to 3.5% are obtained with a 500 mV control signal at a modulation frequency of ≈6.5 MHz. With a resonant optical response that can be spectrally tuned by design, modulators based on the artificial electrostrictive effect may be used for laser Q-switching and mode-locking among other applications that require modulation at megahertz frequencies.
电致伸缩是所有天然电介质的特性，即在电场作用下它们会发生机械变形。本文证明了一种由硅和氧化铟锡制成的介电纳米线阵列组成的人工超材料纳米结构，在电场作用下可实现可逆的结构变形，并且这种重新配置伴随着光学传输和反射的显著变化，从而提供了强大的电光效应。这种超材料可用作光谱可见到近红外部分的电光调制器的功能元件。本文演示了一种工作在 1550nm 波长的调制器，其有效电致伸缩系数和电光系数分别约为 10mV 和 10mV。在调制频率约为 6.5MHz 时，用 500mV 的控制信号可获得高达 3.5%的传输变化。通过设计可以对其共振光学响应进行光谱调谐，基于人工电致伸缩效应的调制器可用于激光 Q 开关和锁模等需要在兆赫兹频率下进行调制的应用。
