Reducing pulsewidth broadening in L-band EDFAs by use of a new L-band EDF

Due to a small effective area of erbium-doped fiber (EDF), a short pulse will be broadened because of self-phase modulation when it is amplified in an L-band EDF amplifier (EDFA); hence, it is necessary to develop a new EDF with large Er/sup 3+/ concentration to reduce the EDF length and a large effective area to reduce the nonlinear effect in the L-band EDFA. In this letter, it will be demonstrated that the pulsewidth can be maintained when a short pulse is amplified in an L-band EDFA consisting of a new L-band EDF.