| 摘要 |
PURPOSE:To provide an antireflection film having excellent mechanical strength, easily, by forming a porous antireflection film on a glass element, wherein the difference between the refractive index of the surface of the substrate glass and that of the antireflection film is specified. CONSTITUTION:A glass substrate is treated with an aqueous solution containing 0.01-1mol/l of a weakly alkaline acidic salt (e.g. Na2HASO4, NaHCO3, etc.), 0-0.1mol of Al<3+> [Al(NO3)3, etc.] and 8.0X10<-4>-1X10<-3>mol/l of Si<4+>(Na2O SiO2, etc.) to form an antireflection film on the substrate. The difference between the refractive index of the interface of the glass substrate and that of the surface of the antireflection film becomes <=0.15, and an optical glass coated with an antireflection film having high mechanical strength can be produced. |
