Balancing Simulation and Fabrication: Substrate Thickness Effects in Terahertz Fano Metasurfaces

The substrate thickness critically influences metasurface transmission properties. While thicker substrates offer cost and fabrication advantages, they incur higher computational demands, prolonged simulation times, and significant spectral distortions due to internal light reflections. The thin substrate is fragile, and the device is difficult to commercialize. In this study, Fano metasurfaces are fabricated on silicon substrates of varying thicknesses for water and ethanol detection. When the substrate thickness exceeds 100 μm, the fFano and sensitivity remain nearly identical. This work establishes an optimal substrate thickness that balances simulation efficiency and fabrication feasibility for high-performance terahertz Fano metasurfaces based on split-ring resonators metasurfaces.