Functional Metamaterial Absorbers for THz Applications

Terahertz (THz) regime which is sandwiched between microwave and optical regions refers to the frequency band of 0.1-10 THz. Because of the lack of natural materials that respond to THz regime, this regime may be the least developed frequency band. But, the advent of metamaterials opens a new way for achieving the THz functional devices. Metamaterials have numerous practical applications such as absorbers, antennas, filters, switches due to their unique electromagnetic responses. Among those, THz metamaterial absorbers play an important role in THz imaging, sensing, detecting, and so on. Most of early developed THz metamaterial absorbers have a drawback of narrow bandwidth due to the strong electromagnetic resonance at a certain frequency, which greatly limits their practical applications. Therefore, many efforts have been devoted to designing broadband metamaterial absorbers with simple resonant structure. Reflecting this urgent demand, this book is written for the purpose of summarizing the recent studies on functional metamaterial absorbers in the THz regime. We hope that this book is helpful for experts and researchers in this field.