Developing perfect Plasmonic absorber as an optical surface based on pyramidal element with Nobel metal and composite

Abstract

In the field of optical device design, some structures, such as absorbers, can be quite challenging to fabricate due to their complexity. In such cases, composite materials can offer a viable solution for developing and manufacturing these intricate structures. One type of composite, namely DNA-metal, can be employed to address this challenge. This study comprises three main sections: the design of a pyramidal element as a dual-band Plasmonic absorber, operating at 1790 nm (with 94.4% absorption) and 2519 nm (with 99.9% absorption); the utilization of a new material based on the Drude model to replace a complex initial model; and the incorporation of the basic structure as an optical sensor. Additionally, a perfect absorber is designed for 2455 nm, achieving a remarkable 99.9% absorption and a high Q-factor. The investigation of this element aims to elucidate its role in the absorber and the interaction between layers to achieve optimal absorption. The finite integrated technique (FIT) is employed for simulating this absorber. Finally, the absorber is utilized for optical sensing, specifically based on redshift, by evaluating sensitivity and the figure of merit (FOM). The interaction between the layers of the absorber element is leveraged to achieve a dual-band response and increase the effective length of the nanostructure.