3D Printed Al2O3 for Terahertz Technology

摘要

In this work we demonstrate that 3D printed Al ₂ O ₃ is a promising material for prototyping and precise fabrication of quasi-optical devices in the terahertz frequency range. The 3D printed Al ₂ O ₃ exhibits a low absorption coefficient ( $lpha < 2extrm {cm}^{-1}$ at 1 THz) and a high refractive index ( $n >3$ ). The printing resolution in the sub $50~mu ext{m}$ range allows for the implementation of structures in the 0.3-3.0 THz range on the subwavelength scale. Furthermore, the printing process enables the realization of crystalline solids, which allows the use of the Al ₂ O ₃ birefringence effect. Here, a $Delta n pprox ~0.05$ was achieved and used for the implementation of $lambda $ /2-wave plates working at ~1 THz. The material properties and wave plates were characterized using a terahertz time-domain spectrometer.