Hello Ravil,in one of my system Dwdm at ultra narrow spacing,i have checked the performance if bessel and gaussian filter for nrz rz and mdrz.I have found that bessel worked good for rz nrz and gaussian for mdrz.i have checked the paper to varify my results with the the i have given below
1.6 Tbps High Speed Long Reach DWDM System by … – Inpressco