Imaging through Nonlinear Metalens Using Second Harmonic Generation
Imaging through Nonlinear Metalens Using Second Harmonic Generation
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DOI：
10.1002/adma.201703843
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发表时间：
2018-02
影响因子：
29.4
通讯作者：
C. Schlickriede;N. Waterman;B. Reineke;P. Georgi;Guixin Li;Shuang Zhang;T. Zentgraf
中科院分区：
文献类型：
--
作者：
C. Schlickriede;N. Waterman;B. Reineke;P. Georgi;Guixin Li;Shuang Zhang;T. Zentgraf
光在超表面的突然相变为波操纵提供了高度灵活性，而无需通过色散材料积累传播相位。在线性光学领域，超表面的一个重要应用领域是平面超透镜成像，与传统的光学微透镜系统相比，它可以实现器件小型化和像差校正。随着将非线性响应纳入无源超表面，预计超透镜的光学功能将进一步丰富，从而带来全新的应用领域。在这里，演示了将超薄平面透镜的功能与同步频率转换相结合的非线性超透镜成像。利用这种非线性超透镜，实验证明了用近红外光对物体进行成像，同时图像出现在可见频率范围的二次谐波信号中。此外，可以通过切换圆偏振基波的旋向性来修改这些非线性超透镜的功能，从而形成真实或虚拟的非线性图像。非线性超透镜不仅能够通过可见光探测器实现红外光成像，而且能够通过超薄超表面器件调制非线性光学响应，同时基波不受影响，从而提供了新型光电器件的非线性信息处理能力。
The abrupt phase change of light at metasurfaces provides high flexibility in wave manipulation without the need for accumulation of propagating phase through dispersive materials. In the linear optical regime, one important application field of metasurfaces is imaging by planar metalenses, which enables device miniaturization and aberration correction compared to conventional optical microlens systems. With the incorporation of nonlinear responses into passive metasurfaces, optical functionalities of metalenses are anticipated to be further enriched, leading to completely new application areas. Here, imaging with nonlinear metalenses that combine the function of an ultrathin planar lens with simultaneous frequency conversion is demonstrated. With such nonlinear metalenses, imaging of objects with near infrared light while the image appears in the second harmonic signal of visible frequency range is experimentally demonstrated. Furthermore, the functionality of these nonlinear metalenses can be modified by switching the handedness of the circularly polarized fundamental wave, leading to either real or virtual nonlinear image formation. Nonlinear metalenses not only enable infrared light imaging through a visible detector but also have the ability to modulate nonlinear optical responses through an ultrathin metasurface device while the fundamental wave remains unaffected, which offers the capability of nonlinear information processing with novel optoelectronic devices.