Hello Taha Ali
According to your question about performance of DCF and FBG,i am agree with Alessandro that it vary for some systems and configuration.There are lot of research articles regarding this particular topic however different results shown about best performance of DCF and FBG.According to my knowledge,DCF has around 93% efficient to reduce pulse width of dispersed signal while FBG have 73% efficiency. Also DCF is costlier than FBG. I have given link of ↓ optiwave dispersion compensation example and a link of paper describing pulse width reduction efficiency of FBG and DCF
http://www.ncbi.nlm.nih.gov/pubmed/25322426