Thickness measurement of thin dielectric film using metallic mesh

Metallic mesh, a metallic thin film with regularly spaced openings, acts as a band-pass filter in the terahertz region. In a certain spectral range, its transmittance becomes higher than the open-area ratio and its resonant transmission spectrum is affected by the dielectric constant in and above the openings. Therefore, metallic mesh can be used as a sensitivity-enhancing material if samples are placed on the metal surface. Here, we report the measurement of thickness at a resolution of 1 mum for thin dielectric films and two-dimensional (2D) imaging using metallic mesh.