Antireflection coating with consistent near-neutral color on complex-shaped substrates prepared by ALD

Color distortions of common antireflective (AR) multilayer coatings are detrimental to their appearance. These are due to the shift of the reflectance maxima toward shorter wavelengths at oblique incidence angles. Layer thickness variations of coatings on inclined surfaces of complex-shaped components additionally contribute to strong color variations. To improve the residual color consistency, a near-neutral color AR coating has been developed and deposited by atomic layer deposition (ALD) on complex-shaped substrates. This results in a uniform color appearance across the optical surface.