Ferromagnetic Driven THz Filters with Sectioned 3D Printed Cells

Development of terahertz sources and technologies based on them in areas such as spectroscopy, visualization, or remote sensing requires inexpensive, efficient devices and materials to control the THz radiation. Devices whose characteristics can be automatically changed over time without mechanical movements are also relevant. In this work, we report on the first results on possibilities of creating controlled spectral selective liquid THz filters. Developed filter based on a cuvette with a magnetic fluid (5% dispersion of 5BDSR particles in 80W-90 synthetic oil), placed in the path of THz radiation between a pair of crossed Helmholtz coils. To increase spectral selectivity, 3D printed linear plastic gratings with different spacing and orientation were placed into a quartz or polymer cuvette. These 3D printed lattices set some regularity in the distribution of magnetic particles, which ensures spectral selectivity.