A metamaterial absorber is proposed that functions in the medium‐ (3–5 µm) and long‐wavelength (8–12 µm) infrared (medium‐wavelength infrared, MWIR, and long‐wavelength infrared, LWIR, respectively) regions. The proposed design, which consists of periodic cells, can be tuned to achieve single‐band or dual‐band light absorption by changing the periodicity of the structure. Each cell forming the metamaterial absorber consists of a bottom metal plate (Al), a top metal disk (Ti), and an intermediate dielectric medium (Si or ZnS) in which a metal disk (Ti) is embedded. For a period of 0.85 µm, the absorber achieves broadband absorption in the LWIR region, with an average absorption of 92.1%. Further, the absorber shows acceptable tolerance to irradiation at oblique incidence. For a period of 2 µm, a peak absorption of 99.05% is achieved in the MWIR region, thereby providing dual‐band absorption. Tuning the periodicity of the structure enhances the localized surface plasmon resonance, with the absorption mechanism explained by establishing an equivalent parallel LC circuit. The absorption properties demonstrated by the proposed metamaterial absorber are promising for thermal imaging and infrared spectroscopy.

中文翻译：

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基于具有高吸收和可调光谱吸收带的简单钛盘的红外超材料宽带吸收器

提出了一种超材料吸收体，该吸收体可在中（3–5 µm）和长波长（8–12 µm）红外（分别为中波长红外，MWIR和长波长红外，LWIR）区域工作。所提议的设计由周期单元组成，可以通过更改结构的周期进行调整，以实现单波段或双波段光吸收。形成超材料吸收体的每个单元均由底部金属板（Al），顶部金属盘（Ti）和其中嵌入金属盘（Ti）的中间介电介质（Si或ZnS）组成。在0.85 µm的时间内，吸收体在LWIR区域实现宽带吸收，平均吸收率为92.1％。此外，吸收剂对斜入射的辐射显示出可接受的耐受性。在2 µm的时间内，峰值吸收为99。MWIR区域达到05％，从而提供了双频带吸收。调整结构的周期性可增强局部表面等离子体激元共振，其吸收机理可通过建立等效的并联LC电路来解释。所提出的超材料吸收剂所展示的吸收特性对于热成像和红外光谱很有希望。