Integrating absorber with non-planar plasmonic structure for k-vector matching absorption enhancement

Plasmonic structure (PS) has recently been demonstrated to provide full control of dispersion characteristics by virtue of spoof surface plasmonic polariton (SSPP). In this paper, a comprehensive scheme is proposed, which develops the non-planar PS as a covering on the absorber to enhance the k-vector matching absorption in a wider frequency band. Owing to the dispersion engineering of SSPP, our theoretical investigation shows that the PS covering based on a straight wire array can not only enhance the k-vector matching absorption of the ground absorber at low frequency, but also achieve the broadband absorption at high frequency. As a proof, two hybrid plasmonic metamaterial absorbers (PMAs) based on the combinations of PS covering and various absorbers are proposed here. Simulations and experimental measurements demonstrate that two kinds of hybrid PMAs can simultaneously achieve broadband absorption enhancement, especially for the lower-frequency absorption. Our proposed strategy succeeds in the comprehensive utilization of dispersion engineering for broadband absorption enhancement, and a wide range of applications is expected to emerge from our design concept ranging from microwave to optical frequencies.Plasmonic structure (PS) has recently been demonstrated to provide full control of dispersion characteristics by virtue of spoof surface plasmonic polariton (SSPP). In this paper, a comprehensive scheme is proposed, which develops the non-planar PS as a covering on the absorber to enhance the k-vector matching absorption in a wider frequency band. Owing to the dispersion engineering of SSPP, our theoretical investigation shows that the PS covering based on a straight wire array can not only enhance the k-vector matching absorption of the ground absorber at low frequency, but also achieve the broadband absorption at high frequency. As a proof, two hybrid plasmonic metamaterial absorbers (PMAs) based on the combinations of PS covering and various absorbers are proposed here. Simulations and experimental measurements demonstrate that two kinds of hybrid PMAs can simultaneously achieve broadband absorption enhancement, especially for the lower-frequency absorption. Our proposed strategy succeeds in the compre...