High accuracy and high sensitivity environmental fiber optic sensor with corrugations
First Claim
1. An apparatus for detecting presence of a measurand, comprising:
- a fiber field access block;
a corrugated measurand sensitive layer over said fiber field access block; and
means for detecting changes in a parameter selected from the group of thickness and index of refraction of said measurand sensitive layer caused by interaction with said measurand; and
wherein said fiber field access block has a clad fiber positioned such that a portion of said clad fiber is exposed to said measurand sensitive layer and any cladding on said portion of said clad fiber is thinner than required to prevent an evanescent wave from escaping said clad fiber.
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Accused Products
Abstract
An apparatus for detecting a measurand includes a fiber field access block having a clad fiber positioned in the fiber field access block such that a portion of the fiber is exposed to an outer surface and any cladding on that portion of the clad fiber is thinner than required to prevent an evanescent wave from escaping the clad fiber. A measurand sensitive layer is provided over the outer surface. A grating is present in either the measurand sensitive layer or the fiber. An optical source and an optical detection component are coupled to the clad fiber. The optical detection component measures shifts in output signals resulting from presence of the measurand in the environment of the fiber field access block caused by changing Bragg conditions which result from swelling of the measurand sensitive layer. The concentration of the measurand can be determined from the detected shifts.
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Citations
29 Claims
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1. An apparatus for detecting presence of a measurand, comprising:
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a fiber field access block; a corrugated measurand sensitive layer over said fiber field access block; and means for detecting changes in a parameter selected from the group of thickness and index of refraction of said measurand sensitive layer caused by interaction with said measurand; and wherein said fiber field access block has a clad fiber positioned such that a portion of said clad fiber is exposed to said measurand sensitive layer and any cladding on said portion of said clad fiber is thinner than required to prevent an evanescent wave from escaping said clad fiber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus for detecting presence of a measurand, comprising:
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a fiber field access block; a measurand sensitive layer over said fiber field access block; and means for detecting changes in a parameter selected from the group of thickness and index of refraction of said measurand sensitive layer caused by interaction with said measurand; wherein said fiber field access block has a clad corrugated fiber positioned such that a portion of said corrugated fiber is exposed to said measurand sensitive layer and any cladding on said portion of said corrugated fiber is thinner than required to prevent an evanescent wave from escaping said corrugated fiber. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A method for detecting a measurand, comprising the steps of:
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providing a fiber field access block having a clad fiber positioned therein such that a portion of said clad fiber is exposed to an outer surface of said fiber field access block and any cladding on said portion of said clad fiber is thinner than required to prevent an evanescent wave from escaping said clad fiber; providing a corrugated measurand sensitive layer over said outer surface of said fiber field access block; positioning said fiber field access block in an environmental matrix; providing an optical signal through said clad fiber; and measuring an optical signal produced from said clad fiber. - View Dependent Claims (23, 24, 25, 26)
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27. A method for detecting a measurand, comprising the steps of:
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providing a fiber field access block having a clad corrugated fiber positioned therein such that a portion of said corrugated fiber is exposed to an outer surface of said fiber field access block and any cladding on said portion of said corrugated fiber is thinner than required to prevent an evanescent wave from escaping said corrugated fiber; providing a measurand sensitive layer over said outer surface of said fiber field access block; positioning said fiber field access block in an environmental matrix; providing an optical signal through said corrugated fiber; and measuring an optical signal produced from said corrugated fiber. - View Dependent Claims (28, 29)
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Specification