Study on multi-wavelength thin film thickness determination method

This work introduces a novel method for measuring thin film thickness，employing a multi-wavelength method that significantly reduces the need for broad-spectrum data. Unlike traditional techniques that require sev⁃ eral hundred spectral data points，the multi-wavelength method achieves precise thickness measurements with data from only 10 wavelengths. This innovation not only simplifies the process of spectral measurement analysis but al⁃ so enables accurate real-time thickness measurement on industrial coating production lines. The method effective⁃ ly reconstructs and fits the visible spectrum（400-800 nm）using a minimal amount of data，while maintaining measurement error within 7. 1%. This advancement lays the foundation for more practical and efficient thin film thickness determination techniques in various industrial applications.