a fiber optic amplifier is disclosed utilizing a doped fiber to provide amplification through stimulated emission . the doped fiber is simultaneously pumped by multiple pump lasers generating optical waves of differing wavelengths . the optical waves from the lasers are combined using a wavelength division multiplexer before introduction into the doped fiber . the use of multiple pump lasers decreases the power requirements of each laser , reduces the cost of the amplifier , and increases reliability without compromising the gain of the amplifier .