Lipworth Guy, Mrozack Alex, Hunt John, Marks Daniel L, Driscoll Tom, Brady David, Smith David R
J Opt Soc Am A Opt Image Sci Vis. 2013 Aug 1;30(8):1603-12. doi: 10.1364/JOSAA.30.001603.
We introduce the concept of a metamaterial aperture, in which an underlying reference mode interacts with a designed metamaterial surface to produce a series of complex field patterns. The resonant frequencies of the metamaterial elements are randomly distributed over a large bandwidth (18-26 GHz), such that the aperture produces a rapidly varying sequence of field patterns as a function of the input frequency. As the frequency of operation is scanned, different subsets of metamaterial elements become active, in turn varying the field patterns at the scene. Scene information can thus be indexed by frequency, with the overall effectiveness of the imaging scheme tied to the diversity of the generated field patterns. As the quality (Q-) factor of the metamaterial resonators increases, the number of distinct field patterns that can be generated increases-improving scene estimation. In this work we provide the foundation for computational imaging with metamaterial apertures based on frequency diversity, and establish that for resonators with physically relevant Q-factors, there are potentially enough distinct measurements of a typical scene within a reasonable bandwidth to achieve diffraction-limited reconstructions of physical scenes.
我们引入了超材料孔径的概念，其中一种潜在的参考模式与设计好的超材料表面相互作用，以产生一系列复杂的场模式。超材料元件的共振频率在很宽的带宽（18 - 26千兆赫）上随机分布，这样孔径会根据输入频率产生快速变化的场模式序列。随着操作频率的扫描，超材料元件的不同子集变得活跃，进而改变场景处的场模式。因此，场景信息可以通过频率来索引，成像方案的整体有效性与所产生场模式的多样性相关。随着超材料谐振器的品质因数（Q值）增加，可以产生的不同场模式数量增加，从而改善场景估计。在这项工作中，我们为基于频率分集的超材料孔径计算成像提供了基础，并确定对于具有实际相关Q值的谐振器，在合理带宽内对典型场景可能有足够多不同的测量值，以实现物理场景的衍射极限重建。
