Multispectrum Electromagnetic Response in FeNiHo/C Heterodimensional Structure for Microwave Absorption and Multimode Photodetection

Abstract Multispectrum response technology is the key to developing multifunctional electromagnetic devices in cross‐field applications. Traditional methods rely on integrating complex multi‐material systems, leading to bulkier and costlier devices. Here, a hierarchical heterodimensional structure composed of FeNiHo alloy and carbon matrix achieves autonomous multispectrum‐coupling electromagnetic response between microwave and ultraviolet through polar interface engineering. In the microwave band, the heterodimensional structure exhibits outstanding microwave absorption performance with high reflection loss of −46.87 dB and ultra‐wide absorption bandwidth of 8.96 GHz. Furthermore, the antenna arrays based on the heterodimensional structure demonstrate in situ microwave frequency‐agile property by a coupled ultraviolet stimulation, where the largest frequency modulation range reaches 5.05 GHz in Ku‐band. In the ultraviolet band, multimode photodetectors constructed by the heterodimensional structure possess excellent responsivity and accurate decoding ability for anti‐interference ultraviolet communication. Particularly, the metamaterial detector achieves analog signal communication for the first time by microwave‐ultraviolet coupling response. This work pioneers a novel approach to developing multifunctional electromagnetic materials for multispectrum applications.