In this study, Passive Edge Filter was designed using Erbium Doped Fiber. When this design was done, simulation was performed to monitor gain changes with respect to −5, −10, − 15, −20 dBm input signal power and varying lengths of I6 EDF which design by FibeCore company. As a result of the simulation, we have experimentally studied using the optimal EDF length of 20 m. As a result, a passive filter with a correlation coefficient of 0.99 with a bandwidth of approximately 21 nm was realized.