Attenuating filter for ultraviolet light
First Claim
1. An attenuating filter providing a prescribed attenuation of the intensity of transmitted ultraviolet light over a predefined wavelength range according to a predefinable spatial distribution of a spectral transmittance, the attenuating filter comprising:
- a substrate fabricated from a transparent material; and
at least one filter coating applied to a surface of the substrate;
the filter coating comprising at least one layer fabricated from a dielectric material that absorbs over a predefined wavelength range, wherein the thickness, measured perpendicular to the surface of the substrate, of the filter coating varies continuously over the surface of the attenuating filter, whereby a spatial variation of the transmittance of the filter coating across the surface of the attenuating filter is obtained.
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Accused Products
Abstract
An attenuating filter provides a prescribed attenuation of the intensity of transmitted, short-wavelength, ultraviolet light, in particular, at wavelengths below 200 nm, that is governed by a predefinable spatial distribution of its spectral transmittance. The filter has a transparent substrate (3), e.g. fabricated from crystalline calcium fluoride. A filter coating (5) fabricated from a dielectric material that absorbs over a predefined wavelength range is applied to at least one surface (4) of the substrate. In the case of operating wavelengths of about 193 nm, the filter coating consists largely of tantalum pentoxide. Filters of the type, which may be inexpensively fabricated with high yields, are noted for their high abilities to withstand laser radiation and may be effectively antireflection coated employing simply designed antireflection coatings.
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Citations
38 Claims
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1. An attenuating filter providing a prescribed attenuation of the intensity of transmitted ultraviolet light over a predefined wavelength range according to a predefinable spatial distribution of a spectral transmittance, the attenuating filter comprising:
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a substrate fabricated from a transparent material; and
at least one filter coating applied to a surface of the substrate;
the filter coating comprising at least one layer fabricated from a dielectric material that absorbs over a predefined wavelength range, wherein the thickness, measured perpendicular to the surface of the substrate, of the filter coating varies continuously over the surface of the attenuating filter, whereby a spatial variation of the transmittance of the filter coating across the surface of the attenuating filter is obtained. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An attenuating filter providing a prescribed attenuation of the intensity of transmitted ultraviolet light over a predefined wavelength range according to a predefinable spatial distribution of a spectral transmittance, the attenuating filter comprising:
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a substrate fabricated from a transparent material; and
at least one filter coating applied to a surface of the substrate;
the filter coating comprising at least one layer fabricated from a dielectric material that absorbs over a predefined wavelength range, wherein the thickness, measured perpendicular to the surface of the substrate, of the filter coating varies over the surface of the attenuating filter, thereby obtaining a spatial variation of the transmittance of the filter coating across the surface of the attenuating filter.
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20. An attenuating filter comprising:
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a substrate fabricated from a transparent material; and
at least one filter coating applied to a surface of the substrate;
the filter coating comprising at least one layer fabricated from a dielectric material that contains tantalum oxide and that absorbs over a predefined wavelength range, and the filter providing a prescribed attenuation of the intensity of transmitted ultraviolet light over a predefined wavelength range at wavelengths of less than about 200 nm according to a predefinable spatial distribution of a spectral transmittance. - View Dependent Claims (21, 22)
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23. An attenuating filter comprising:
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a substrate fabricated from a transparent material; and
at least one filter coating applied to a surface of the substrate;
the filter coating comprising at least one layer fabricated from a dielectric material that absorbs over a predefined wavelength range, wherein the dielectric material from which the layer of the filter coating is fabricated contains at least one metal oxide;
a dielectric antireflection coating is arranged on the filter coating; and
the attenuating filter provides a prescribed attenuation of the intensity of transmitted ultraviolet light over a predefined wavelength range in the ultraviolet spectral region at wavelengths of less than about 200 nm according to a predefinable spatial distribution of a spectral transmittance. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification