3D-Printed Phase Wave Plates for Creation of Terahertz Beams with Linear Power Distribution

We calculate the profile of a phase plate for an operating frequency of 100 GHz, which allows one to obtain a beam with the most uniform power distribution in the region 384 × 6 mm at a distance of 50 cm, using the Gerchberg–Saxton iterative algorithm. A series of phase plates made of polyamide was 3D-printed. The parameters of the phase plate measured experimentally agree well with the theoretical calculations. The depth resolution of the image and the dependence of the beam profile on the frequency of the incident radiation are also studied. The obtained results are of practical use in the field of nondestructive control for the creation of linear terahertz scanners.