Stitched Long-Period Fiber Gratings for Gain-Flattening of Broadband EDFAs

摘要

In this paper, we report the optimal designs of stitched long-period fiber gratings (SLPGs) for gain-flattening of broadband erbium-doped fiber amplifiers (EDFAs) by using the genetic algorithm. Two measured gain spectra with bandwidth of 50nm and 80nm have been flattened within ± 0.64dB and ± 0.73dB, respectively, by using optimally designed SLPG devices. Such an SLPG device possesses not only a flexible spectrum-shaping capability, but also a simple index-modulation profile suitable for practical implementation. The point-by-point grating writing technique is employed to demonstrate the fabrication of the designed SLPG filters.