Zhaoxuan Zheng, Zaijin Li, Qi Wu, Fei Lin, Yishui Lin, Ganghuang Liu, Runhe Bai, Wei Luo, Dongxin Xu, Yi Qu
A seven-layer broadband antireflection coating consisting of Al2O3, TiO2, SiO2, and MgF2 was designed and deposited on both sides of K9 glass for the 400-1100 nm range. The deposition parameters for TiO2 and SiO2 single layers were optimized, and the measured optical constants were used in TFCalc to refine the multilayer design. Layer-specific thickness-tolerance analysis was performed to identify the layers requiring strict process control. The initially characterized double-sided coating showed an average transmittance of 98.72% over 400-1100 nm. Four samples prepared in one additional deposition batch exhibited closely matching transmittance spectra, indicating low sample-to-sample variation within that batch. Five-position profilometry indicated consistent total-thickness control. Cross-sectional scanning electron microscopy (SEM) revealed well-defined multilayer contrast without obvious cracking, and regional energy-dispersive X-ray spectroscopy (EDS) analysis detected the constituent elements of the coating. These results demonstrate a practical design-to-fabrication approach that combines process-specific optical constants with tolerance analysis, with potential applications in imaging systems, optical windows, and lidar.