A conventional multimode fiber was used to sample EDFA output and the spectrum of EDFA was measured by an optical spectrum analyzer (YOKOGAWA AQ6370D) in the near-IR spectral region. The fiber attenuation was measured by cut-back method. The Tungsten lamp was used as the whitelight source. An optical spectrum analyzer (YOKOGAWA AQ6370D) was used for spectral measurement in the near-IR spectral region. A 300 mm focal length scanning spectrometer (Bentham Instruments TMc300) was used for all spectral measurements at mid-infrared wavelengths, which has a 300 lines/mm grating and a liquid-nitrogen-cooled InAs detector (Electro-Optical Systems S-010-LN4).