Bragg grating fabrication with wide range coarse and fine wavelength control.

A Bragg grating fabrication method based on a phase-controlled interferometric approach with both coarse control and fine tuning of Bragg wavelength in the range of 1200-2200 nm is demonstrated by fabricating multiple Bragg reflectors in a single fiber device. With the fine tuning method, we achieved ~113 nm of FWHM bandwidth centered at ~1545 nm and ~174 nm of FWHM bandwidth centered at ~2005 nm, which were limited only by the size of the overlap of the interfering beams and by the Bragg wavelength. We used the wide range of the coarse wavelength control and the precision of the fine wavelength setting to determine the fiber Sellmeier coefficients with a mean squared error <3.

Correction of systematic errors in the fabrication of fiber Bragg gratings.

We suggest a novel method for significant improvement of fiber Bragg grating (FBG) spectral characteristics based on compensation of repeatable errors during the grating writing process. The method is based on an open loop scheme in which a test grating is written first and then a corrected design is obtained and implemented by writing another (compensated) grating. The results are presented for a FBG dispersion compensator.