THz diffractive lens manufactured using 3D printer working for 0.6 THz

Rapid development of terahertz technologies causes constant search for new possibilities of making optical elements, needed for proper beam shaping. Large optical elements are often used in THz setups to collect as much power as possible. Unfortunately, traditional refractive optical lenses significantly absorb already weak signal. This is the reason for searching for new solutions in the form of diffractive optical elements (DOEs). For higher terahertz frequencies however, it is challenging to find an appropriate material as well as uncomplicated manufacturing methods. In this article, we present a higher-order kinoform (HOK) made of paraffin, cast from 3D-printed mold, efficiently working for 0.6 THz.