一种实现任意偏振调控中波红外消色差超表面的正向计算方法

A forward calculation method to quickly realize the achromatic metasurface for arbitrary polarization control

人工微结构超表面近年来在偏振调控与色散调控领域都取得了诸多进展,然而传统方法计算超表面结构对椭圆偏振态的调控效果需要对每一个数据求解方程,因此实现任意偏振的消色差调控依然在复杂度上是一个挑战。一种基于坐标变换的正向计算方法用以快速计算超表面单元对任意偏振态的调控效果被提出,利用纯硅体系下的椭圆柱结构作为调控单元设计了工作在中红外波段的对椭圆偏振态调控的消色差聚焦超表面透镜。结果表明,此种方法与设计在极大简化计算流程的情况下,能够有效实现对椭圆偏振态的操控。相比于之前所报道的基于圆偏振或无偏振依赖的设计,该方法进一步拓展了超表面色散调控的应用范围,具有广阔的应用前景。

In recent years,many advances have been made in polarization control and dispersion control of artificial microstructure.However,it is still a challenge to realize achromatic control of arbitrary polarization because the traditional way to calculate the manipulation of metasurface on elliptic polarization have to solve the equation for each piece of data.A direct calculation method based on coordinate transformation is proposed to quickly calculate the manipulation of metasurface elements on arbitrary polarization states.An achromatic focusing metasurface lens based on all-Si elliptic cylinder structure is designed to manipulate elliptical polarization states in the mid-infrared band.The result shows that this method and design can effectively control the elliptic polarization state under the condition of greatly simplifying the calculation process.Compared with the previously reported design based on circular polarization or non-polarization dependence,the application scope of the dispersion control of the metasurface is further expanded.