Co-Polarization Wideband Terahertz Metamaterial Absorber with a Wavy Split Ring Resonator

A simple design of co-polarization wideband metamaterial absorber (MA) for terahertz devices is proposed, where the wavy split ring resonator has been conceived to broaden the absorption bandwidth of MA. Simulation results ensure that the average absorptivity of proposed MA reaches above 90% ranging from 2.07 THz to 4.80 THz. The relative absorption bandwidth (RAB) of proposed MA is 79.47%. In addition, the proposed MA may also be considered as a wideband polarization converter with high efficiency. The physical mechanism of wideband absorption is analyzed by using the electric field and the surface current distributions. The co-polarization absorption characteristics of proposed MA under oblique incident angle are also investigated. For TE mode, the absorptivity of proposed MA reaches above 81% ranging from 2.07 THz to 4.80 THz for incident angles below 40°. For TM mode, the proposed MA still retains absorptivity above 87% ranging from 2.07 THz to 4.80 THz for incidence angles below 40°. Due to the compact structure and co-polarization wideband absorption with wide incident angle stability, the proposed MA may be widely utilized for medical imaging, material detecting and stealth technology. Moreover, the wavy split ring resonator can be also applied to achieve wideband absorption in various frequency regions from microwave to visible light.