光控电磁超材料研究进展

电磁超材料是由亚波长尺寸单元周期或非周期排列组成的人工结构，能对电磁波的频率、幅度、相位和极化等基本物理特征进行调控，突破了传统材料的限制，可实现很多自然界不存在的有趣物理现象及应用。过去二十余年，超材料因其强大的电磁调控能力一直是物理领域的研究热点。但无源超材料在电磁波调控中存在局限性，如工作频率固定、实现功能单一等。所以，可调有源超材料越来越受关注。通过引入有源元器件，超材料的功能可通过外部激励信号进行动态调控，在实际应用中具有重要意义。目前常用的控制方式包括电控、温控、光控和机械控制等，其中光控具有可远程调控、无接触式控制、调制速度快以及结构简单等优点。该文概述了近年来光控电磁超材料的研究进展，从直流、微波、太赫兹和光频段4种不同频段分别介绍现有光控超材料和超表面的工作，重点介绍其工作机制和应用场景，并对这一快速发展领域进行总结和展望。 

Research Progress of Light-controlled Electromagnetic Metamaterials

Electromagnetic metamaterials are artificial structures composed of a periodic or aperiodic arrangement of subwavelength unit cells and can regulate the physical characteristics of electromagnetic waves, such as their frequency, amplitude, phase, and polarization. Metamaterials overcome many limitations of traditional materials and can be used to realize interesting physical phenomena and applications that do not occur in nature. Over the past two decades, metamaterials have become a focus in the fields of physics and electronics owing to their powerful electromagnetic regulation ability. However, passive metamaterials have limitations in electromagnetic wave regulation, such as fixed operating frequency and single function. As such, increasing attention is being paid to tunable and active metamaterials. By introducing active elements, the functions of metamaterials can be dynamically regulated by external excitation signals, which is highly significant for practical applications. At present, commonly used control methods include electrical, temperature, light, and mechanical controls, among which light control has the advantages of remote and noncontact control, a fast modulation speed, and a simple structure. In this study, we summarize the latest progress in light-controlled electromagnetic metamaterial research, and introduce recent work on light-controlled metamaterials and metasurfaces in direct currents, microwaves, terahertz waves, and optics. We focus primarily on relevant operational mechanisms and application scenarios and discuss future prospects.