Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
An optical window comprising a substrate of material having high transparency over a desired spectral range of infrared radiation, a protective layer of a material of high resistance to rain erosion, said protective layer being thin as compared to the substrate and of such thickness that it does not materially affect the optical properties of the window, and a layer of non-crystalline bonding material joining said protective layer to said substrate, said bonding material being a glass which is transparent in said spectral range, and which has a refractive index close to the refractive index of at least one of the protective layer and the substrate, and a softening temperature below the melting points of the protective layer and the substrate.
Claim 2
Dependent Claim
121 words
An optical window comprising a substrate of material having high transparency over a desired spectral range of infrared radiation, a protective layer of a material of high resistance to rain erosion, said protective layer being thin as compared to the substrate and of such thickness that it does not materially affect the optical properties of the window, and a layer of non-crystalline bonding material joining said protective layer to said substrate, said bonding material being a glass which is transparent in said spectral range, and which has a refractive index close to the refractive index of at least one of the protective layer and the substrate, and a softening temperature below the melting points of the protective layer and the substrate.
Claim 3
Dependent Claim
15 words
An optical window as defined in claim 1 in which said substrate is zinc selenide.
Claim 4
Dependent Claim
17 words
An optical window as defined in claim 1 in which said bonding material is a chalcogenide glass.
Claim 5
Dependent Claim
32 words
An optical window as defined in claim 3 in which said glass has a composition by weight of about 40% to 20% arsenic, about 40% to 60% sulfur, and about 20% selenium.
Claim 6
Dependent Claim
22 words
An optical window as defined in claim 1 in which the substrate is zinc selenide and the protective layer is zinc sulfide.
Claim 7
Dependent Claim
17 words
An optical window as defined in claim 5 in which the bonding material is a chalcogenide glass.
Claim 8
Dependent Claim
59 words
An optical window as defined in claim 1 in which said substrate is a material selected from the group consisting of zinc selenide, barium fluoride, sodium chloride, potassium chloride and gallium arsenide, said protective layer is a material selected from the group consisting of zinc sulfide, calcium fluoride and magnesium fluoride, and said bonding material is a chalcogenide glass.
Claim 9
Dependent Claim
32 words
An optical window as defined in claim 7 in which said glass has a composition by weight of about 40% to 20% arsenic, about 40% to 60% sulfur, and about 20% selenium.