Comparison of chromatic dispersion compensation techniques for WDM-PON solution

The upper transmission range of the wavelength division multiplexing passive optical network (WDM-PON) can be restricted by chromatic dispersion (CD). This paper contains the investigation of till 16-channel WDM-PON system with efficient CD pre-compensation and post-compensation methods. It is shown that CD offset has a marginal role for guaranteed optical link downstream performance and maximum length of high-speed WDM-PON system. The results show that employment of extra 7 km long dispersion compensating fiber (DCF) placed in central office (pre-compensation configuration) enhances the WDM-PON network link length by 19.3% (from 57 km up to 68 km), but if extra 2 km long DCF fiber is used in remote terminal (post-compensation configuration) link length can be extended up to 5.3% (from 57 km to 60 km). It was found that usage of fiber Bragg grating (FBG) in central office (pre-compensation configuration) improves network reach up to 26.3% (from 57 km up to 72 km), but using this FBG for CD post-compensation in remote terminal network reach can be improved by 15.8% or 9 km in length - from 57 km to 66 km. Basis on the results authors recommend to use FBG as the best solution for CD compensation in pre-compensation configuration (before SMF line) in future high speed long-reach DWDM-PON systems.