Ultrathin broadband nearly perfect absorber with symmetrical coherent illumination
Ultrathin broadband nearly perfect absorber with symmetrical coherent illumination
复制标题
具有对称相干照明的超薄宽带近乎完美的吸收体
DOI：
10.1364/oe.20.002246
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发表时间：
2012-01-30
期刊：
影响因子：
3.8
通讯作者：
Luo, Xiangang
中科院分区：
文献类型：
--
作者：
Pu, Mingbo;Feng, Qin;Luo, Xiangang
正如最近的文章所强调的那样[Phys. Rev. 105，053901（2010）和Science 331，889-892（2011）]，本征硅板中窄带完全吸收的相干控制已经引起了很多关注。在本文中，我们证明了宽带相干完美吸收体（CPA）可以通过重掺杂的单晶硅薄膜实现。在对称相干光照射下，导出了两种不同的理想吸收区，即极宽和中等窄的带宽。带宽的大幅度提高可能为宽带应用开辟新的途径。随后，使用干涉方法来控制吸收相干与极大的对比度之间的最大和最小吸收率。与文献中的结果相比，薄膜CPA在工作频率和带宽上都表现出更大的灵活性。(C)2012美国光学学会
As highlighted by recent articles [Phys. Rev. Lett. 105, 053901 (2010) and Science 331, 889-892 (2011)], the coherent control of narrowband perfect absorption in intrinsic silicon slab has attracted much attention. In this paper, we demonstrate that broadband coherent perfect absorber (CPA) can be achieved by heavily doping an ultrathin silicon film. Two distinct perfect absorption regimes are derived with extremely broad and moderately narrow bandwidth under symmetrical coherent illumination. The large enhancement of bandwidth may open up new avenues for broadband applications. Subsequently, interferometric method is used to control the absorption coherently with extremely large contrast between the maximum and minimum absorptance. Compared with the results in literatures, the thin film CPAs proposed here show much more flexibility in both operation frequency and bandwidth. (C) 2012 Optical Society of America