Optimization of probe tip for enhanced imaging performance in THz s-SNOM

THz s-SNOM is a high-resolution imaging technique widely used for nanoscale material characterization. However, most research on THz s-SNOM has focused on enhancing the resolution, with less attention devoted to optimizing other key imaging quality metrics. The present study systematically investigates the impact of different probe tips on imaging performance, particularly resolution, SNR, and contrast, via both simulations and experiments. The results demonstrate that probe tips exert distinct effects on each metric and that a balance must be struck depending on the specific applications. Building on these findings, we propose an optimization strategy for the probe tip radius of curvature to balance resolution, SNR, and contrast for specific applications. This work provides valuable insights into the optimization of THz s-SNOM, with implications for materials science, nanotechnology, and biomedical imaging.