An All-Fibre Dynamic Gain Equalizer Based on a Novel Long-Period Fibre Grating Written by High-Frequency CO₂ Laser Pulses

An all-fibre dynamic gain equalizer based on a novel long-period fibre grating (LPFG) written on a photosensitive fibre by high-frequency CO₂ laser pulses is demonstrated for the dynamic gain flattening of Er-doped fibre amplifiers. The resonant peak amplitude of such a dynamic gain equalizer can be adjusted linearly by bending the LPFG. The gain profile of the Er-doped fibre amplifier constructed has been flattened to within ±0.7 dB over a 32 nm bandwidth using such a device.