New design for a quad-band metamaterial absorber with a single resonator

What is it about?

Metamaterials are materials designed to have properties not found in nature. For example, they can be designed to obtain perfect absorption of light. But, in general, they only show a single absorption peak. This means they absorb light in a single region. While absorbers with more absorption peaks can be designed, it makes them more complex. This is because more peaks need more resonators (components that decide which region of light is absorbed). In this study, the authors present a simple design for a quad-band absorber. A quad-band absorber is one with four absorption peaks. But, instead of four resonators, the authors use a single resonator. It consists of a vertical metallic strip that connects two horizontal strips to form an uneven I-shape. The authors show that this design absorbs terahertz or sub-millimeter light in four different regions. To understand how the absorber works, the authors perform simulations. They find that the absorber's performance depends on the dimensions of the strip. Next, they present a second absorber, in which the vertical strip is made of light-sensitive silicon. This allows them to adjust the number of peaks by changing the current flow in the silicon strip. Based on these results, the device can find applications in fields related to terahertz technology.

Featured Image

Photo by Erfan Afshari on Unsplash

Photo by Erfan Afshari on Unsplash

Why is it important?

Metamaterial absorbers with multiple absorption peaks have many useful applications. These include harvesting solar energy, sensing, detection, and imaging. But such devices use multiple resonators in their design. This makes the absorber bulky and complex. In addition, it shows poorer absorption. As a result, a good strategy is to reduce the number of resonators. KEY TAKEAWAY: This study presents a simple design for a metamaterial absorber with a single resonator. The absorption of this device can be changed by changing the resonator dimension or the current flow in it.