DESIGN AND CONTROL OF GAIN-FLATTENED ERBIUM-DOPED FIBER AMPLIFIER FORWDM APPLICATIONS

A simple experimental method to design gain-flattened erbium-doped fib er amplifier is proposed and demonstrated based on the two linear rela tions between the output power and the pump power, and between the gai n and the length of the erbium-doped fiber at the gain flattened state . The spectral gain variation of the erbium-doped fiber amplifier cons tructed by this method was less than 0.4 dB over 12 nm (1,545 similar to 1,557 nm) wavelength region. The gain flatness is also controlled w ithin 0.4 dB over the input power range of -30 similar to -15 dBm/ch t hrough the feedback control utilizing the amplified spontaneous emissi on power in the 1,530 nm region.