| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 463487 | Optical Fiber Technology | 2011 | 5 Pages |
A reference grating method for characterizing low-reflectance Bragg gratings in a polarization maintaining (PM) fiber and the corresponding state of polarization (SOP) is presented, and experimentally demonstrated through a fast inline characterization of a PM twin (0.5% + 0.5%) fiber Bragg gratings (FBGs) during the fabrication. The polarization extinction ratio of the pre-set system SOP was determined to be 15.0 dB. The reflectivity measurement for the first grating was carried out while writing the target grating to 1.39%, then in-situ annealing, until after-annealing with a reflectivity of 0.49%. The spectra of the second grating and the combined gratings were characterized by the same way. The combined twin PM FBGs had a bandwidth of 0.515 nm, a center wavelength of 974.304 nm, and a reflectivity of 1.03%. The speed was normally 5 s, and was 3 s without characterizing the system SOP. The reflectivity measurement accuracy was 0.049%.
► We present a reference grating method for characterizing low-reflectance Bragg gratings in a polarization maintaining (PM) fiber and the corresponding state of polarization (SOP). ► A practical application of this method was demonstrated in fast online characterizing a twin PM FBGs with 0.5% + 0.5% reflectivity and 0.5 nm BW during the fabrication process. ► The reflectivity of the first grating and the combined twin gratings were 0.49% and 1.03%, respectively. ► The speed was normally 5 s. Without characterizing the system SOP, the speed was 3 s.
