Gain flattening by long period gratings in erbium doped fibers

摘要

In this paper we have proposed a novel technique of gain flattening of erbium doped fiber amplifier (EDFA) in which a long period grating is written in the erbium doped fiber (EDF) itself. The salient feature of the proposed technique is that in addition to usual gain flattening, there is an enhancement in average gain in the 1540-1560 nm band. To obtain the gain characteristics of the EDF with the grating we have developed the coupled mode theory that includes gain term of the EDF.