Comparative analysis of light transmission in thin-film materials across multiple laser wavelengths using partial least squares regression

Thin-film composites have significance in optoelectronics, photonics, and sensing technologies because of their unique optical properties. This work examines the light transmission behavior of six thin-film materials: Cu, ZnO, Ni, MoS₂, MoS₂–SiC, and ITO/MoS₂ under continuous wave (CW) laser irradiation at wavelengths of 405, 532, 670, 830, and 980 nm. The experimental results were analyzed using Partial Least Squares Regression (PLSR) to derive material-specific optical fingerprints and multivariate spectral responses. The PLSR model achieved a root mean squared error (RMSE) of 3305.17 and identified more than 95 % of the variance with five latent components. MoS₂ had the highest transmission at 405 nm, followed by Ni at 532 and 980 nm, and ZnO at 830 nm. Cu continuously had the lowest transmission. These findings provide important insights into the wavelength-dependent behavior of thin films and can help guide material selection and optimization for application in transparent electrodes, optical coatings, photodetectors, and laser-based systems.