Abstract: Accurate wavelength calibration is crucial for the reliable performance of transmission holographic spectrometers, which are widely used in analytical chemistry, materials science, and biomedical research. However, inherent optical aberrations in the focusing components often cause systematic wavelength errors—particularly when the available emission lines from standard calibration sources are unevenly distributed over the measurement range. To address this challenge, we propose a novel error calibration method that leverages the inherent symmetry of aberration-induced errors in transmission optics. Our approach involves generating an error calibration function by combining polynomial fitting with symmetry-based averaging, thereby compensating for systematic residual errors across the spectral range. Experimental validation using two widely employed atomic emission lamps demonstrated that the maximum wavelength calibration error was reduced by 20%–27% compared with conventional calibration methods. This improvement enhances the precision of spectrometric measurements and provides an effective, easily implemented supplement to existing wavelength calibration protocols, especially under challenging spectral coverage conditions.
