Rapid fabrication of terahertz lens via three-dimensional printing technology

We design a plano-convex lens working in the terahertz (THz) frequency range and fabricate it using three-dimensional (3D) printing technology. A 3D field scanner is used to measure its focal properties, and the results agree well with the numerical simulations. The refractive index and absorption coefficient measurements via THz time-domain spectroscopy (THz-TDS) reveal that the lens material is highly transparent at THz frequencies. It is expected that this inexpensive and rapid 3D printing technology holds promise for making various THz optical elements.