Abstract
We intend to produce a fiber laser amplifier by constructing a hybrid system of Erbium doped fiber amplifier and fiber Raman amplifier, to obtain the effect of gain flattening. And we try to optimize the gain of the signal laser by adjusting the length and location of Erbium doped fiber. Comparing to those fiber amplifiers which only use Erbium doped fiber or which only use fiber Raman amplifier, this hybrid system has some unique advantages.