It is expected to achieve many disruptive functions through artificial structures, such as photonic bandgap, negative refractive index, subdiffraction imaging, and so on. In recent years, with the development of micro/nanofabrication technology, it has been discovered that artificial structures have many physical properties not occurring in traditional materials. The curved profile and large weight of refractive/reflective lenses and mirrors hinder the development of next-generation optical systems, especially in integrated space telescopes and wearable optical devices and systems. Under the classical optical theoretical framework, the surfaces of both the refractive and reflective lenses are shaped to be curved to bend the light trajectory. Meanwhile, the molecules in crystals reach equilibrium states under the action of many molecular forces, thereby forming regular and orderly structures, which determine their mechanical, thermal, electromagnetic, and optical properties. From celestial bodies and buildings to the atomic and molecular structure of common materials, the structures of various scales determine their basic functions, wherein the underlying physical laws of the interaction between substances are called “structural–functional relationship.” For example, the law of universal gravitation determines that most celestial bodies are approximately spherical in shape and move in nearly elliptical orbits. The viewpoint of this paper may push further researches on the structural-functional relationship of artificially structured materials and devices, and find broad application prospects in imaging, communication, photonic chips, among many others.įor quite a long time, structures and functions of matters are the core of physics researches. In particular, we reviewed several typical methods for the study of optical/electromagnetic structural-functional relationships, including semi-classical analytical models, heuristic optimization methods, deep neural networks, topological optimization methods, etc. Based on the analogy of mechanics and optics/electromagnetism, the concept of “Electromagnetic Architectures” is proposed. This article reviews the optical/electromagnetic properties and performance of typical artificial micro/nanostructures. In recent years, with the development of photonic crystals, metamaterials, metasurfaces, and other related disciplines, the relationship between the structures and functionalities of artificial optical/electromagnetic materials and devices has become a research hotspot.