Interference Coating Adhesion via Silicon Oxide Mediator

The patent introduces an intermediate layer comprising silicon oxide deposited between the low refractive index layer (formed from organosilicon compounds) and the high refractive index layer. This intermediate layer acts as a mediator that improves adhesion between the two layers, preventing cracking while maintaining optical performance. The silicon oxide layer creates a gradual transition in material properties, reducing the abrupt interface that causes adhesion failure.

The patent employs a composite multilayer structure combining organic/organosilicon compounds with inorganic metal oxides. The interference coating consists of alternating layers of low refractive index (from organosilicon compounds) and high refractive index (from metal oxides like TiO2, ZrO2, Ta2O5). This composite structure leverages the advantages of both material types: the organosilicon layers provide flexibility and adhesion, while the metal oxide layers provide hardness and optical performance, resulting in a coating that resists cracking under mechanical and thermal stress.

The patent applies local quality by using different material compositions in different layers of the interference coating. The low refractive index layers are formed from organosilicon compounds which provide excellent adhesion properties, while the high refractive index layers are formed from inorganic metal oxides that provide thermal resistance and optical performance. Each layer is optimized for its specific function, creating a heterogeneous structure where adhesion and thermal resistance are both satisfied in their respective locations.