Redundant core in multicore optical fiber for safety
AssigneeIntuitive Surgical Operations, Inc.
InventorsMark E. Froggatt, Dawn K. Gifford, Jeffrey T. Lacroix, Patrick Roye, Alexander K. Sang
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Abstract
An optical fiber includes multiple optical cores configured in the fiber including a set of primary cores and an auxiliary core. An interferometric measurement system uses measurements from the multiple primary cores to predict a response from the auxiliary core. The predicted auxiliary core response is compared with the actual auxiliary core response to determine if they differ by more than a predetermined amount, in which case the measurements from the multiple primary cores may be deemed unreliable.
Claims20
An interferometric measurement system for measuring an optical fiber including multiple primary cores configured in the optical fiber and an auxiliary core configured in the optical fiber, the system comprising:
- interferometric detection circuitry configured to detect measurement interferometric pattern data associated with each of the multiple primary cores and the auxiliary core;
- and
- data processing circuitry configured to:
- determine compensation parameters based on the detected measurement interferometric pattern data for the multiple primary cores, the compensation parameters compensating for variations between a calibration configuration of the multiple primary cores and an actual configuration of the multiple primary cores,
- compare a predicted parameter value for the auxiliary core with a measurement-based parameter value for the auxiliary core to produce a comparison,
- determine an unreliability of the determined compensation parameters based on the comparison, and
- generate a signal in response to the unreliability.
An interferometric measurement method for measuring an optical fiber including multiple primary cores configured in the optical fiber and an auxiliary core configured in the optical fiber, the method comprising:
- detecting, using interferometric detection circuitry, measurement interferometric pattern data associated with each of the multiple primary cores and the auxiliary core when the optical fiber is in a sensing position;
- and
- determining, using data processing circuitry, compensation parameters based on the detected measurement interferometric pattern data for the multiple primary cores, the compensation parameters compensating for variations between a calibration configuration of the multiple primary cores and an actual configuration of the multiple primary cores,
- comparing a predicted parameter value for the auxiliary core with a measurement-based parameter value for the auxiliary core to produce a comparison,
- determining an unreliability of the compensation parameters based on the comparison, and
- generating a signal in response to the unreliability.
An optical fiber comprising:
- a plurality of cores comprising:
- a central core placed along a neutral axis of the fiber, and
- a plurality of peripheral cores, the plurality of peripheral cores comprising four or more primary peripheral cores and an auxiliary peripheral core, wherein each peripheral core of the plurality of peripheral cores is at a respective radius distance from the central core,
- wherein at least one of the four or more primary peripheral cores includes a different dopant than the remaining primary peripheral cores to provide a temperature response different than a temperature response of the remaining primary peripheral cores of the plurality of cores, and
- wherein the four or more primary peripheral cores are at a first radius distance from the central core and the auxiliary peripheral core is at a second radius distance from the central core, and
- wherein the plurality of peripheral cores has an average radius distance from the central core, and wherein a difference between the first radius distance and the second radius distance is at least 10% of the average radius distance.
Dependencies are inferred from the claim text.