Simple and affordable spectrum analyzer for the THz radiation range

A simple, compact, and cost-efficient setup for the spectral characterization of sub-THz and THz beams is proposed. It utilizes, the well-known property of the diffraction gratings to redirect the radiation at an angle dependent on the frequency. In the presented reflective configuration only a single moving element is necessary - a rotary stage. A set of diffraction gratings with varying constants has been manufactured using laser-cutting and served for the experimental verification of the setup. The results are consistent with the theory and prove the feasibility of the THz spectrum analyzer.