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A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber betwee

A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

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What is claimed is: 1. A fiber polarimeter comprising: a fiber having an input for receiving a light wave, an output and an axis, the fiber including a fiber Bragg grating inscribed at an angle to the axis so that two portions of the light wave input to the fiber, depending upon the polarization of

What is claimed is: 1. A fiber polarimeter comprising: a fiber having an input for receiving a light wave, an output and an axis, the fiber including a fiber Bragg grating inscribed at an angle to the axis so that two portions of the light wave input to the fiber, depending upon the polarization of the light wave, are coupled out of the fiber spatially separated with intensity maximums occurring in different polarization states; and monitoring detectors coupled to measure light from the fiber Bragg grating. 2. The fiber polarimeter as recited in claim 1 wherein the fiber Bragg grating comprises: at least two fiber Bragg gratings inscribed at respective angles in the fiber; and a wave plate disposed in the fiber between the at least two fiber Bragg gratings. 3. The fiber polarimeter as recited in claims 1 or 2 further comprising means for calculating four Stokes parameters from the measurement data in order to determine polarization, degree of polarization and/or power of the light wave. 4. The fiber polarimeter as recited in claim 2 wherein the respective angles have the same orientation with respect to the axis. 5. The fiber polarimeter as recited in claim 2 wherein the respective angles have different orientations with respect to the axis. 6. The fiber polarimeter as recited in claim 2 wherein the fiber Bragg gratings and the wave plate have respective orientations such that all intensity maximums or minimums occur in different polarizations of the light wave. 7. The fiber polarimeter as recited in claim 2 wherein the fiber Bragg gratings and the wave plate have respective orientations and the fiber Bragg gratings have parameters such that all intensity maximums or minimums occur in different polarizations of the light wave that have greatest possible distances from each other on a Poincare sphere. 8. The fiber polarimeter as recited in claim 2 wherein the wave plate is produced by a method selected from the group consisting of ultra-violet (UV) induced birefringence in the core of the fiber, compressive loading of the fiber, looping of the fiber and inserting a section of linear birefringent fiber in the fiber. 9. The fiber polarimeter as recited in claims 1, 2, 4, 5, 6, 7 or 8 wherein the fiber is selected from the group consisting of a single-mode standard fiber, a single-mode fiber having a doping profile and a birefringent fiber. 10. The fiber polarimeter as recited in claims 1 or 2 wherein each fiber Bragg grating is produced by means of a photo mask. 11. The fiber polarimeter as recited in claims 1 or 2 wherein the detecting means comprises appropriately dimensioned detectors adjusted according to intensity maximums from each fiber Bragg grating and fixedly coupled to the fiber. 12. The fiber polarimeter as recited in claim 11 wherein the appropriately dimensioned detectors are grouped as detector pairs for each fiber Bragg grating. 13. The fiber polarimeter as recited in claim 2 wherein the fiber Bragg gratings and wave plate are oriented and dimensioned so that polarization dependent losses of the fiber Bragg gratings compensate for each other. 14. The fiber polarimeter as recited in claim 1 wherein the fiber Bragg grating comprises: a plurality of fiber Bragg gratings inscribed in the fiber; and a plurality of wave plates disposed in the fiber between consecutive ones of the fiber Bragg gratings. 15. The fiber polarimeter as recited in claim 14 wherein the fiber Bragg gratings are oriented and have coupling-out efficiencies dimensioned so that polarization dependent losses of each fiber Bragg grating is compensated by the subsequent fiber Bragg grating in the fiber. 16. The fiber polarimeter as recited in claims 1 or 2 further comprising a birefringent polarization maintaining fiber coupled to the output of the fiber. 17. The fiber polarimeter as recited in claim 1 further comprising a birefringent polarization maintaining fiber coupled to the output of the fiber with the fiber Bragg grating located at a position selected from the group consisting of in the fiber adjacent to the output and in the birefringent polarization fiber adjacent to the output of the fiber. 18. A polarimetric method comprising the steps of: coupling a light wave into a fiber having a fiber Bragg grating inscribed in the fiber at an angle to an axis of the fiber; and coupling at least two portions of the light wave, depending upon the polarization of the light wave, out of the fiber at the fiber Bragg grating, the two portions being spatially separated with intensity maximums occurring at different polarization states. 19. The polarimetric method as recited in claim 18 further comprising the step of detecting each portion coupled out of the fiber at the fiber Bragg grating to provide measurement data. 20. The polarimetric method as recited in claims 18 or 19 wherein the fiber Bragg grating comprises at least two fiber Bragg gratings inscribed in the fiber and a wave plate disposed in the fiber between the at least two fiber Bragg gratings. 21. The polarimetric method as recited in claim 20 further comprising the step of calculating from the measurement data four Stokes parameters from which polarization, degree of polarization and/or power for the light wave are determined. 22. The polarimetric method as recited in claim 20 wherein the detecting step comprises the step of coupling a plurality of detectors to the fiber according to the intensity maximums from each fiber Bragg grating. 23. The polarimetric method as recited in claim 22 wherein the plurality of detectors are grouped in pairs for each fiber Bragg grating.