Frequency-multiplexing for imaging at submillimeter waves

We present simulation results on transmission-type element with optimized local transmission function at submillimeter waves. The element can be considered as a part of illuminating quasioptics for single-pixel imaging. The planar element is based on stacked layers of 497-μm silicon wafers. The wide-band transmission function is achieved with perforations in each layer, which realize the desired effective permittivity in the volume of the stacked layers. We have optimized the element for 220-330 GHz, with the transmission function producing frequency-multiplexed Hadamard-basis patterns.