An optical fiber with microgratings for increased measurable strain range
AssigneeIntuitive Surgical Operations, Inc.
InventorsMark E. Froggatt, Dawn K. Gifford, Alexander K. Sang
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Abstract
An optical fiber with one or more microgratings is disclosed. Methods and apparatus are described for making an optical fiber with one or more microgratings. Methods and apparatus are described for an optical fiber with one or more microgratings. Optical sensing methods and an optical sensing system effectively decouple strain range from the laser tuning range, permit the use of a smaller tuning range without sacrificing strain range, and compensate for ambiguity in phase measurements normally associated with smaller tuning ranges.
Claims20
An optical sensor comprising:
- an optical fiber including multiple cores;
- first microgratings inscribed in the multiple cores at a common first location along a length of the optical fiber;
- and
- second microgratings inscribed in the multiple cores at a common second location along the length of the optical fiber;
- wherein each of the first and second microgratings has a grating length of less than 50 μm.
A method for making an optical fiber sensor in an optical fiber comprising multiple cores, the method comprising:
- generating an ultraviolet light beam;
- splitting the ultraviolet light beam into a first ultraviolet light beam and a second ultraviolet light beam;
- focusing the first ultraviolet light beam so the first ultraviolet light beam is narrower in width than the second ultraviolet light beam;
- crossing the first ultraviolet light beam and the second ultraviolet light beam to form an interference pattern that extends across the multiple cores of the optical fiber;
- and
- exposing the optical fiber to the interference pattern at a first location along a length of the optical fiber to inscribe first gratings in the multiple cores at the first location.
An optical sensor comprising:
- an optical fiber including multiple cores;
- first microgratings created in the multiple cores at a first location along a length of the optical fiber by exposure of the optical fiber at the first location to an interference pattern extending across the multiple cores;
- and
- second microgratings created in the multiple cores at a second location along the length of the optical fiber by exposure of the optical fiber at the second location to the interference pattern extending across the multiple cores,
- wherein the interference pattern results from crossing a focused first ultraviolet light beam with a second ultraviolet light beam that is wider than the first ultraviolet light beam.
Dependencies are inferred from the claim text.