Sensing systems and few-mode optical fiber for use in such systems
AssigneeCorning Incorporated
InventorsMing-Jun Li, Shenping Li
Life of this patent
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Abstract
A sensing optical fiber comprising: a few-moded multi-segment core, said core comprising one core segment surrounded by another core segment, and at least one cladding surrounding said core; said core having an F factor (μm2) of 100 μm2 to 350 μm2, and is constructed to provide (i) an overlap integral between the fundamental optical guided mode and the fundamental acoustic guided mode of greater than 0.7 and (ii) the overlap integral between the LP11 optical guided mode and the fundamental acoustic guided mode at least 0.45.
Claims20
A sensing optical fiber comprising:
- a few-moded multi-segment core, said core comprising one core segment surrounded by another core segment, and at least one cladding surrounding said core;
- said core having an F factor (μm2) of 100 μm2 to 350 μm2, and is constructed to provide (i) an overlap integral between the fundamental optical guided mode and the fundamental acoustic guided mode of greater than 0.7 and (ii) the overlap integral between the LP11 optical guided mode and the fundamental acoustic guided mode at least 0.45.
A sensing optical fiber comprising:
- a few-moded multi-segment core, said core comprising first core segment surrounded by another core segment, and at least one cladding surrounding said core;
- wherein the refractive index delta of said one core segment is lower than the refractive index delta of said another core segment, said core having a core radius of 4 μm≦r≦20 μm and F factor (μm2) is 100 μm2 to 350 μm2 is constructed to provide (i) an the overlap integral between the fundamental optical guided mode and the fundamental acoustic guided mode is greater than 0.7 and (ii) overlap integral between the LP11 optical guided mode and the fundamental acoustic guided mode of at least 0.45.
A distributed Brillouin optical fiber sensing system, comprising:
- a sensing optical fiber configured to support at least first and second guided modes, said sensing fiber having a core constructed to provide (i) an the overlap integral between the fundamental optical guided mode and the fundamental acoustic guided mode is greater than 0.7 and (ii) overlap integral between the LP11 guided optical mode and the fundamental acoustic guided mode of at least 0.45;
- a first pump light source optically coupled to the sensing optical fiber and configured to generate first pump light that travels in the sensing optical fiber in the first guided mode and forms a Brillouin dynamic grating (BDG) that contains information of a local Brillouin frequency of the sensing optical fiber;
- a probe light source optically coupled to the sensing optical fiber and configured to generate pulsed probe light that travels in the sensing optical fiber in the second guided mode, with the pulsed probe light having a wavelength selected so that at least a portion of the pulsed probe light reflects from the Brillouin dynamic grating and includes information about the local Brillouin frequency and a probe-light reflection location;
- and
- a receiver optically coupled to the sensing optical fiber and configured to receive the reflected probe light and determine the local Brillouin frequency, the reflection location, and at least one condition along the sensing optical fiber.
Dependencies are inferred from the claim text.