Tunable long-period fiber gratings for EDFA gain and ASE equalization

We use, for the first time, tunable long-period fiber gratings (LPFG's) to facilitate the gain equalization of an erbium-doped fiber amplifier (EDFA). The ASE and gain peak of an EDFA at a wavelength of 1532 nm were equalized by 7.5 and 3 dB, respectively, at 37 mW pump laser power. The flattened bandwidth was 12 nm (1526–1538 nm).