We demonstrate a mechanically reconfigurable terahertz filter implemented by the 3D-printed all-dielectric metagrating, providing a versatile platform for adaptive photonic devices. The structure consists of parallel supporting bars connected by vertical grating elements, forming a lattice that can be mechanically reconfigured. By applying a controlled lateral displacement to the supporting bars, the grating elements are tilted, effectively reducing the grating period and inducing a systematic blue shift in the transmission dip frequency. By tilting the metagrating, we experimentally observed a 15% frequency modulation and a 95% transmission modulation. The numerical simulations show consistent results with the experimental results. In contrast to conventional approaches that rely on refractive index modulation, phase-change materials, or other active tuning mechanisms, this method achieves tunability purely through geometric reconfiguration. This strategy offers a simple, low-cost, and robust route to dynamic terahertz filtering, and it can be readily extended to other reconfigurable metamaterials and photonic devices requiring adaptive control of their optical response.
Lee et al. (2026) studied this question.