Broad Terahertz Radial Perfectly Symmetric Gradient Honeycomb All-Dielectric Planar Luneburg Lens

We propose an all-dielectric broad terahertz planar Luneburg lens with radial gradient honeycomb structure. Exquisite microstructure in the form of radial symmetric honeycomb column within subwavelength dimension was put forward to satisfy the requirement of refractive index of Luneburg lens. The results of full-wave simulation demonstrate excellent performance of our designed lens. Far field radiation pattern of the present lens is highly directive, incident waves could be concentrated on the opposite side of the lens with high convergence, and its operating frequency spans from 0.06THz to 0.24THz. Our design has great potential to be applied in terahertz communication and imaging via the growing 3D printing technology.