Optical device with fiber Bragg grating and narrowband optical source
First Claim
1. An optical device comprising:
- a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating, wherein the fiber Bragg grating has a power transmission spectrum comprising a plurality of local transmission minima comprising a first local transmission minimum comprising a Bragg wavelength of the fiber Bragg grating, a second local transmission minimum on a short wavelength side of the Bragg wavelength, and a third local transmission minimum on a long wavelength side of the Bragg wavelength;
a narrowband optical source of at or in the vicinity of a local transmission maximum between a pair of neighboring local transmission minima of the plurality of local transmission minima, the local transmission maximum having a maximum power at a transmission peak wavelength;
at least one optical detector in optical communication with the fiber Bragg grating;
at least one coupler in optical communication with the narrowband light source, wherein, during operation of the optical device, the at least one coupler splits the light from the narrowband optical source into a first portion having the wavelength and propagating along a first optical path extending along and through the length of the fiber Bragg grating to the at least one optical detector and into a second portion having the wavelength and propagating along a second optical path different from the first optical path;
a fiber loop, wherein at least a portion of the fiber loop comprises the fiber Bragg grating, wherein the first optical path extends in a first direction along the fiber loop and the second optical path extends in a second direction along the fiber loop, the second direction opposite to the first direction; and
wherein the at least one coupler is optically coupled to the narrowband optical source and the fiber loop, wherein, during operation of the optical device, the first portion and the second portion are recombined by the at least one coupler after propagating along and through the length of the fiber Bragg grating, wherein the at least one optical detector comprises a detector of changing optical phase of the recombined first and second portions resulting from a phase difference between the first portion and the second portion due to perturbation of the fiber Bragg grating.
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Accused Products
Abstract
In certain embodiments, an optical device and a method of use is provided. The optical device includes a fiber Bragg grating having a substantially periodic refractive index modulation along a length of the fiber Bragg grating. The fiber Bragg grating has a power transmission spectrum with a plurality of local transmission minima, wherein each pair of neighboring local transmission minima has a local transmission maximum therebetween. The local transmission maximum has a maximum power at a transmission peak wavelength. The optical device further includes a narrowband optical source in optical communication with a first optical path and a second optical path. The narrowband optical source is configured to generate light having a wavelength at or in the vicinity of a local transmission maximum or at or in the vicinity of a wavelength at which the power transmission spectrum has a maximum slope between a local transmission maximum and either one of two local transmission minima neighboring the local transmission maximum.
27 Citations
30 Claims
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1. An optical device comprising:
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a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating, wherein the fiber Bragg grating has a power transmission spectrum comprising a plurality of local transmission minima comprising a first local transmission minimum comprising a Bragg wavelength of the fiber Bragg grating, a second local transmission minimum on a short wavelength side of the Bragg wavelength, and a third local transmission minimum on a long wavelength side of the Bragg wavelength; a narrowband optical source of at or in the vicinity of a local transmission maximum between a pair of neighboring local transmission minima of the plurality of local transmission minima, the local transmission maximum having a maximum power at a transmission peak wavelength; at least one optical detector in optical communication with the fiber Bragg grating; at least one coupler in optical communication with the narrowband light source, wherein, during operation of the optical device, the at least one coupler splits the light from the narrowband optical source into a first portion having the wavelength and propagating along a first optical path extending along and through the length of the fiber Bragg grating to the at least one optical detector and into a second portion having the wavelength and propagating along a second optical path different from the first optical path; a fiber loop, wherein at least a portion of the fiber loop comprises the fiber Bragg grating, wherein the first optical path extends in a first direction along the fiber loop and the second optical path extends in a second direction along the fiber loop, the second direction opposite to the first direction; and wherein the at least one coupler is optically coupled to the narrowband optical source and the fiber loop, wherein, during operation of the optical device, the first portion and the second portion are recombined by the at least one coupler after propagating along and through the length of the fiber Bragg grating, wherein the at least one optical detector comprises a detector of changing optical phase of the recombined first and second portions resulting from a phase difference between the first portion and the second portion due to perturbation of the fiber Bragg grating. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An optical device comprising:
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a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating; a narrowband optical source in optical communication with the fiber Bragg grating, wherein, during operation of the optical device, the narrowband optical source generates light having a wavelength such that the light is transmitted along the fiber Bragg grating with a group velocity such that a ratio of the speed of light in vacuum to the group velocity is greater than 5; at least one coupler in optical communication with the narrowband optical source, wherein, during operation of the optical device, the at least one coupler splits the light from the narrowband optical source into a first portion having the wavelength propagating along a first optical path extending along and through the length of the fiber Bragg grating and a second portion having the wavelength and propagating along a second optical path different from the first optical path; at least one optical detector in optical communication with the at least one coupler; a fiber loop, wherein at least a portion of the fiber loop comprises the fiber Bragg grating, wherein the first optical path extends in a first direction along the fiber loop and the second optical path extends in a second direction along the fiber loop, the second direction opposite to the first direction; and wherein the at least one coupler is optically coupled to the narrowband optical source and the fiber loop, wherein, during operation of the optical device, the first portion and the second portion are recombined by the at least one coupler after propagating along and through the length of the fiber Bragg grating, wherein the at least one optical detector comprises a detector of changing optical phase of the recombined first and second portions resulting from a phase difference between the first portion and the second portion due to perturbation of the fiber Bragg grating. - View Dependent Claims (19, 20, 21)
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22. A method of using a fiber Bragg grating comprising:
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providing a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating, wherein the fiber Bragg grating has a power transmission spectrum comprising a plurality of local transmission minima comprising a first local transmission minimum comprising a Bragg wavelength of the fiber Bragg grating, a second local transmission minimum on a short wavelength side of the Bragg wavelength, and a third local transmission minimum on a long wavelength side of the Bragg wavelength; generating light from a narrowband optical source, the light having a wavelength at or in the vicinity of a local transmission maximum between a pair of neighboring local transmission minima of the plurality of local transmission minima, the local transmission maximum having a maximum power at a transmission peak wavelength; splitting the light into a first portion having the wavelength and a second portion having the wavelength; transmitting the first portion of the light along a first optical path extending in a first direction along and through a fiber loop comprising the fiber Bragg grating; transmitting the second portion of the light along a second optical path different from the first optical path, the second optical path extending in a second direction along and through the fiber loop, the second direction opposite to the first direction; recombining the first portion and the second portion after propagating along and through the fiber Bragg grating; and detecting a changing optical phase of the recombined first and second portions resulting from a phase difference between the first portion and the second portion due to perturbation of the fiber Bragg grating. - View Dependent Claims (23, 24, 25, 26)
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27. A method of using a fiber Bragg grating comprising:
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providing a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating; generating light from a narrowband optical source, the light at a wavelength having a group velocity such that a ratio of the speed of light in vacuum to the group velocity is greater than 5; splitting the light into a first portion having the wavelength and a second portion having the wavelength; transmitting the first portion of the light along a first optical path extending in a first direction along and through a fiber loop comprising the fiber Bragg grating; transmitting the second portion of light along a second optical path different from the first optical path, the second optical path extending in a second direction along and through the fiber loop, the second direction opposite to the first direction; recombining the first portion and the second portion after propagating along and through the fiber Bragg grating; and detecting a changing optical phase of the recombined first and second portions resulting from a phase difference between the first portion and the second portion due to perturbation of the fiber Bragg grating. - View Dependent Claims (28, 29, 30)
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Specification