Metagrating absorber: design and implementation

The extent to which the introduction of subwavelength spatial modulation of electromagnetic properties improves absorption performances is studied. The proposed absorber represents an evolution from the Salisbury screen, whereby the uniform resistive layer is replaced by a metagrating. A periodic supercell that supports only the specular reflection is first designed, and load impedances are then engineered to suppress this diffraction mode. To experimentally demon-strate the concept, four prototypes are fabricated and tested in the microwave domain around 10 GHz. Furthermore, the performances assessed by a merit factor derived from Rozanov's bound show that the use of metagratings opens up good perspectives for improving the state of the art. Our findings can pave the way toward the development of high performance absorbers for applications across a broad fre-quency spectrum.(c) 2022 Optica Publishing Group

Automated summary

This study investigates the improvement in absorption performances brought about by the introduction of subwavelength spatial modulation of electromagnetic properties. A new type of absorber, replacing the uniform resistive layer with a metagrating, is proposed. Experimental tests conducted in the microwave domain around 10 GHz demonstrate the potential of metagratings for enhancing absorption performance.