  Polymer based stereolithographic additive manufacturing has been established
for the rapid and low-cost fabrication of THz optical components due to its
ability to construct complex 3D geometries with high resolution. For polymer
based or integrated optics, thermal annealing processes are often used to
optimize material properties. However, despite the growing interest in THz
optics fabricated using stereolithography, the effects of thermal annealing on
the THz dielectric properties of polymethacrylates compatible with
stereolithography has not been studied yet. In this manuscript we report on the
THz ellipsometric response of thermally annealed polymethacrylates prepared
using UV polymerization. Our findings indicate that the investigated
polymethacrylate maintain a stable optical response in THz spectral range from
650 to 950 GHz after thermal annealing at temperatures up to 70 degrees C for
several hours.
