Abstract
A hybrid amplifier consisting of one stage of Erbium Doped Fiber Amplifier and two stages of Raman amplifiers is constructed. Two Raman fibers are cascaded in series to suppress the intensity noise due to double Rayleigh scattering. Backward pumping is applied at all stages in order to increase the gain of Erbium Doped Fiber Amplifier and to decrease the polarization dependent gain of Raman fiber amplifier. In our previous experiment a 16 channel Wavelength Division Multiplexed system with channel spacing of 5 nm was considered. In this experiment a Density Wavelength Division Multiplexed system having 80 channels and a channel spacing of 0.8 nm was taken in to account. Gain Flattening is achieved for the entire C-band and L-bands. Experimental results showed that the hybrid amplifier has the average Gain of more than 19 dB in the wavelength range between 1530 and 1600 nm, with the Noise Figure of less than 6 decibels. The Gain of the Erbium Doped Fiber Amplifier and Raman was optimized to minimize the ripple value as low as 0.045 decibels with an output power of 15.265 decibel-milli. (C) 2012 Optical Society of America.