In this thesis, we investigate the double-pumped L-band (1570-1610 nm) amplified spontaneous emission (ASE) fiber source by employing the 1480 nm bi-directional pumping configuration. First, we chose the adequate fiber length, and then adjusted the pump power to optimize the characteristics of the ASE source in different reflectance. The characteristics are experimentally examined and compared in terms of output power, mean wavelength, linewidth, flatness and conversion efficiency in three configurations with forward-forward (FF), forward-backward (FB) and backward-forward (BF) structures. In our experiments, FB configuration with EDF length of 93 m and reflectance of 30 ¢H is the best one to be an L-band ASE fiber source with an output power(POUT) of 71.8 mW, a mean wavelength(£fm) of 1584.3 nm, a linewidth(£G£f) of 41.6 nm, the flatness(£GP) of 1 dB, and the pump conversion efficiency(£b) of 42.2 ¢H.