Hydrogen loading of near net shape optics
AssigneeCorning Incorporated
InventorsKenneth Edward Hrdina, Michael A Mueller, Susan Schiefelbein
Life of this patent
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Abstract
A method of making a fused silica article that is loaded with hydrogen. A fused silica glass near net shape part is provided and is loaded with a molecular hydrogen in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3. The thinner shape of the near net shape part enables the shape to be loaded more quickly than previous methods. A fused silica article loaded with hydrogen using the method is also described.
Claims25
A fused silica article, the fused silica article having a hydrogen concentration in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3 and an index homogeneity of less than about 5 ppm over an area of at least about 25 cm2, wherein hydrogen has been loaded into a near net shape of the fused silica article, wherein the fused silica article is one of a concave optical element, a convex optical element, and a meniscus optical element having a concave surface and a convex surface, and wherein isohydrogen contours in the fused silica article are symmetric along a use direction and the hydrogen concentration decreases from a first external surface and a second external surface opposite the first external surface along the use direction toward an interior point in the fused silica article.
A method of making a fused silica article, the method comprising:
- a. providing a near net shape of the fused silica article;
- b. loading the near net shape with a hydrogen concentration in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3;
- and
- c. finishing the near net shape after loading the near net shape with hydrogen to form the fused silica article, wherein the fused silica article is one of a concave optical element, a convex optical element, and a meniscus optical element having a concave surface and a convex surface, and wherein isohydrogen contours in the fused silica article are symmetric along a use direction toward an interior point in the fused silica article and the hydrogen concentration decreases from a first external surface and a second external surface opposite the first external surface along the use direction.
A method of loading a fused silica near net shape with hydrogen, the method comprising the steps of:
- a. providing the near net shape, wherein the near net shape is a near net shape of one of a concave optical element, a convex optical element, and a meniscus optical element having a concave surface and a convex surface;
- b. exposing the near net shape to a first hydrogen pressure for a first time period, wherein hydrogen diffuses into the near net shape;
- and
- c. reducing the first hydrogen pressure to a second hydrogen pressure;
- and
- d. exposing the near net shape to the second hydrogen pressure for a second time period, wherein the second hydrogen pressure is sufficient to load a region of the near net shape with a hydrogen concentration in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3, wherein isohydrogen contours in the fused silica article are symmetric along a use direction of the near net shape and the hydrogen concentration decreases from a first external surface and a second external surface opposite the first external surface along the use direction toward an interior point in the fused silica article.
A method of making a fused silica article, the method comprising:
- a. providing a near net shape of the fused silica article, wherein the fused silica article is one of a concave optical element, a convex optical element, and a meniscus optical element having a concave surface and a convex surface;
- b. exposing the near net shape to a first hydrogen pressure for a first time period, wherein hydrogen diffuses into the near net shape;
- and
- c. reducing the first hydrogen pressure to a second hydrogen pressure;
- d. exposing the near net shape to the second hydrogen pressure for a second time period;
- e. finishing the near net shape to form the fused silica article, wherein the first and second time periods are sufficient to provide a region of the fused silica article with a hydrogen concentration of in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3, wherein the fused silica article has an index homogeneity of less than about 5 ppm over an area of at least about 25 cm2, and wherein isohydrogen contours in the fused silica article are symmetric along a use direction and the hydrogen concentration decreases from a first external surface and a second external surface opposite the first external surface along the use direction toward an interior point in the fused silica article.
Dependencies are inferred from the claim text.