Area-coded effective medium structures, a new type of grating design.
Area-coded effective medium structures, a new type of grating design.
复制标题
区域编码有效介质结构，一种新型光栅设计。
作者：
B. Kleemann;J. Ruoff;R. Arnold
我们提出了一种新的方法，利用垂直于普通超波长光栅周期的亚波长特征尺寸来设计具有理想衍射性能的光栅。这与众所周知的一维二元燃烧光栅不同，后者使用沿光栅周期的结构，从而在光栅周期方向上产生任意有效折射率分布方面开辟了新的灵活性。由于亚波长特征形成连续的区域，它们被称为区域编码有效介质结构（ACES）。与众所周知的由柱组成的二维排列的二元亚波长结构相比，ACES更稳定，并且具有相当的效率特性。以四能级区域编码有效介质光栅为例，设计了四能级区域编码有效介质光栅的原理，并将其与二元燃烧光栅和可变孔径光栅的效率进行了比较，优化了其亚波长周期。
We propose a new way to design gratings with desired diffraction properties by using subwavelength feature sizes perpendicular to the ordinary superwavelength grating period. This is different from well-known one-dimensional binary-blazed gratings that use a structuring along the grating period and thus opens new flexibility in generating arbitrary effective-index distributions in the direction of the grating period. Since the subwavelength features form contiguous areas, they are called area-coded effective medium structures (ACES). Compared with well-known binary subwavelength structures in two-dimensional arrangements consisting of pillars, ACES are more stable and have comparable efficiency properties. As an example we show how to design in principle a four-level area-coded effective medium grating, compare the efficiency of ACES with binary-blazed and échelette gratings, and optimize the subwavelength period of ACES.