Frequency-Dependent Deconvolution for Enhanced THz-TDS Scans: Accounting for Beam Width Variations in Time Traces

Terahertz time-domain spectroscopy (THz-TDS) is a powerful tool for nondestructive testing, but the quality of scans is limited by beam spreading effects, which vary with frequency. We propose a deconvolution method that accounts for the changing beam width as a function of frequency. By incorporating frequency-specific Gaussian beam profiles, determined through the knife-edge technique, the proposed method enhances the spatial resolution of THz-TDS scans while keeping the ability to analyze the phase of the signals. Our approach significantly improves contrast and sharpness in both reflectance and transmission modes. This technique offers a more accurate and robust enhancement of THz-TDS imaging.