Aluminum oxide (Al2O3) optical films and their applications in the ultraviolet region of the spectrum

Subject of study. We describe the results of a study of aluminum oxide (Al2O3) optical films on a quartz substrate in the ultraviolet and visible regions of the spectrum. Aim of study. The optical constants of the films were measured spectrophotometrically based on the reflection and transmission spectra. Methods. Absorption was taken into account using what we believe to be a novel method for correcting film spectra. Main results. The absorption spectra were used to determine the extinction coefficients of the films, and the absorption-free spectra in the 0.25-0.85 mu m region were used to determine the indices of refraction. Practical significance. The resulting constants were used in the design and fabrication of high-reflectivity mirrors for use in the ultraviolet at 0.22-0.23 mu m. (c) 2023 Optica Publishing Group