3D-printed resin substrates for terahertz liquid crystal phase shifters

A novel fabrication method for liquid crystal (LC) devices in the terahertz (THz) band is proposed, utilizing 3D-printed resin substrates as an alternative to conventional quartz/silicon substrates. By combining established LC device manufacturing processes with vertical electric field modulation, this approach achieves high-efficiency, low-cost, and monolithic integration of THz LC devices. The fabricated phase shifter with a 450 μm-thick LC layer achieved a maximum phase modulation of 99.25° at 0.75 THz. Through indirect experimental testing, it exhibits quarter-wave-plate-like functionality in the 0.725–0.735 THz band. The 3D printing technology employed in this study exhibits unique potential for fabricating LC devices with complex architectures, including flexible and curved configurations, thereby overcoming the inherent limitations of conventional planar fabrication processes. To validate the feasibility of this novel technical approach, THz phase modulation devices have been successfully fabricated. This advancement represents the emergence of an innovative fabrication paradigm capable of circumventing traditional structural design constraints, which is expected to significantly expand the application fields and innovation potential of THz LC devices.