Minin Igor V, Liu Cheng-Yang, Yang Yu-Chih, Staliunas Kestutis, Minin Oleg V
Tomsk State Politechnical University, Tomsk, 36 Lenin Avenue, 634050, Russia.
Tomsk State University, Tomsk, 30 Lenin Avenue, 634050, Russia.
Sci Rep. 2020 May 21;10(1):8459. doi: 10.1038/s41598-020-65292-7.
In this work, we experimentally demonstrate that a thin rectangle dielectric-metal structure can have a function of a flat focusing mirror based on photonic jet effect in reflection mode. Using polydimethylsiloxane (PDMS) rectangle with size length of 10 μm and wavelength-scale thickness of 1 μm on the top of a silicon wafer, we have built a flat mirror which focuses an incident beam at the focal length changing from 1.38 μm to 11.67 μm upon tuning the beam incidence angle from 30° to 75°. The focusing properties of such a mirror persist in the wavelength range of 405 nm to 671 nm. Our approach can be extended to realize other optical functionalities by properly controlling rectangle dimensions and materials. This flat focusing mirror is able to guide the incident beam in free space without perceptible diffraction at the distance equal to the photonic jet length and suitable for small-scale photonic circuits.
在这项工作中，我们通过实验证明，基于反射模式下的光子喷射效应，薄矩形介电-金属结构可以起到平面聚焦镜的作用。我们在硅片顶部使用了尺寸为长10μm、波长尺度厚度为1μm的聚二甲基硅氧烷（PDMS）矩形，构建了一个平面镜，当将光束入射角从30°调至75°时，该平面镜能将入射光束聚焦在焦距从1.38μm变化到11.67μm的位置。这种镜子的聚焦特性在405nm至671nm的波长范围内保持不变。通过适当控制矩形尺寸和材料，我们的方法可以扩展以实现其他光学功能。这种平面聚焦镜能够在自由空间中引导入射光束，在等于光子喷射长度的距离处没有明显的衍射，适用于小规模光子电路。
