Invisibility cloaking with passive and active Huygens's metasurfaces

摘要

According to the Equivalence Principle, any distribution of electromagnetic fields can be generated within a closed region by suitable electric and magnetic sources lying on its bounding surface. In electromagnetic theory, these sources have been used as fictitious analytical tools. However, this has changed in recent years with the development of "Huygens's metasurfaces," which are subwavelength thin sheets of artificial active and/or passive elements. With proper configuration, these elements can physically approximate the aforementioned sources, enabling precise manipulation of electromagnetic waves in extraordinary manners. Given their potential, this work aims to provide an overview of Huygens's metasurfaces with a focus on cloaking applications. After an exposition of general operation and design principles, both active and passive Huygens's cloaks are described.