Abstract This study has clarified various RZ Percentage Duty Cycle Coding with NRZ modulation Technique Signature on The Fiber System Performance. The total form lighted/electrical power after linear measured multimode fiber/FSO channel measured based different RZ percentage duty cycle coding with the assistance of NRZ modulation techniques is performed. The electrical/lighted form measured power after APD receiver with linear multimode fiber/FSO channel measured based different RZ percentage base band form duty cycle coding with the assistance of NRZ modulation techniques is demonstrated. The lighted based band form can be used for the modulation of the based band electrical signal form based on the RZ percentage duty cycle coding with the assistance of NRZ for both linear measured multimode fiber and FSO measured channel.