| 摘要 |
An antireflective optical film exhibits a quintic refractive index profile with an initial refractive index nL as close as possible to the refractive index of the incident medium and a final refractive index nH substantially equal to the refractive index of the substrate. The refractive index profile of the film may be defined by the relationship: n(x)=nL+(nH-nL) (10 (x/T)3-15( x/T)4+6( x/T)5) where N(x) is the refractive index of the film at a depth x in the film relative to the incident surface of the film and T is the thickness of the film. The film may also be fabricated as a plurality of layers, with each layer substantially thinner than wavelengths within the spectral band. Each layer within the plurality is divided into a sublayer pair, including a first sublayer with the refractive index nL and a second sublayer with the refractive index nH, such that the refractive index of each sublayer pair approximates the average refractive index of the corresponding layer as defined by the quintic profile. Each of the layers obeys the relationships: tH=t(n2-nL2)/nH2-nL2) and tL=t-tH where t is the thickness of the layer, n is the average refractive index of the layer, tH is the thickness of the sublayer with the refractive index nH, and tL is the thickness of the sublayer with the refractive index nL.
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