DESIGN CONSIDERATION OF ERBIUM DOPED FIBER FOR EFFICIENT L-BAND EDFAs

In this paper,the relation between gain coefficient of long wavelength band(L band)EDFA and the Er 3 ion concentration of erbium doped fiber (EDF) is analyzed.Very high concentration EDF co doped with aluminium has been developed to shorten the fiber length necessary for L band amplification.L band amplification has been realized with a dual stage pumping scheme.With the total EDF length of 18m,the small signal gain is 42.26dB and the output power is 17.5dBm at 1570nm.The low concentration quenching effect is believed to be due to the high aluminium concentration in author fiber.At-3dBm total input signal power,the gain tilt of 7 WDM channels from 1570 to 1600nm is only 0.68dB.