Multi-layered anti-reflection coating

摘要

A multi-layered anti-reflection coating for use with a plastic substrate is provided. The coating consists of four layers and has high durability. The first layer furthest from the substrate is made of SiO2; the second layer is made of a mixture of ZrO2 and TiO2; the third layer is made of ZrO2; and the fourth layer is made of SiO or SiO2. The optical thicknesses of the first to third layers are about 0.25 lambda with respect to a design wavelength lambda , respectively. However the optical thickness of the fourth layer is greater than that of the respective first to third layers and selected between 0.5 lambda to 2.0 lambda .