Abstract: In the evolution of broadband networks, the WDM PON access network still needs to be upgraded; it should efficiently utilize the entire bandwidth dynamically for maximum number of end users/ONUs. For Dynamic Bandwidth Allocation (DBA), the Optical Line Terminals (OLT), Dynamically Allocate Wavelengths (DWA) to all ONUs and will uniformly distribute the powers with power splitters at remote node. Even though allocating bandwidth uniformly as per user demands is essential, it is necessary to take care of effective utilization of wavelength individually during wavelength allocating process with single hardware component and less cost. In view of this, it is essential that the Fabry Perot Filter (FPF) is considered as tunable filter/ tunable transmitter for replacing more fixed laser sources. Also, it is a low cost device to resonate number of wavelengths dynamically by changing its tunable parameters. In this study, the importance of effective utilization of wavelength using fabry perot filter at OLT has been experimentally analyzed and found that the optimal wavelengths or pulse suited for 10Gbps WDM PON and above for the cost trade off.