Hello Ranjeet
i agree with rajguru that The transmitted signal (A) is fed to a high-Finesse Fabry-Perot etalon (FP) through an optical circulator (OC). you should try to Use cascaded amplifiers, the performance of the system can be enhanced. EDFA when combined with Raman to
form hybrid amplifier it have advantages over individual amplifiers, designed hybrid Raman/EDFA for yielding closed form analysis by considering the fiber non-linearities. observed by combining the Raman/EDFA, maximum repeater-less transmission distance increases compared to individual amplifier.
Try this and see if there is some substantial change in your design.
I hope it will work for you.
Thank you