Design And Simulation Of WDM—PON System Based On Fiber Bragg Grating

With the development of FTTH (fiber to the home) technology, as the representative of the broadband access network technology, the PON’s (passive optical network) level continuously enhance, and in all kinds of PON, WDM—PON obviously is the trend of future development. WDM—PON technology will combine the traditional wave technology and passive optical network technology, which can not only make full use of cable resources, but also can avoid testing range the ONU of the time division multiple access technology, fast bit synchronization and so on many technical difficulties.In short, the WDM—PON is a large capacity、high security、easy to upgrade、a new generation of access network technology.This paper respectively introduces the principle of PON technology and WDM development process from two aspects; especially for the basic principle of WDM technology and various parts of the system made a more detailed description.In many of the WDM—PON scheme, such as a colorless ONU’s WDM—PON requiring a higher cost on optical devices, changing greatly on the existing network, and for the traditional passive optical network, the WDM—PON is a good transition upgrade scheme:we choose WDM technology and bring it into the downlink transmission system,in the uplink, we continues to use the traditional TDM—PON technology.This paper adopts demultiplexer which be made of Fiber Bragg Grating and narrowband filter transmitting the downlink signal of WDM—PON,we design and simulation the system of16channel FBG WDM—PON by the Optiwave software.Set access signal rate is155Mbit/s,622Mbit/s,2.5Gbit/s,10Gbit/s,we observe the eye and Q value of the system.From the experiment of simulation, we can conclude that Bragg Grating has a good channel isolation, side mode suppression characteristic value is greater thanl5dB; when the input signal is smaller than2.5Gbit/s, the value of Q can reaching18、receive sensitivity reaching31.2、the eye diagram is clear, small thickness, power index、and BER are in the ideal range. But when the access signal rate greater than2.5Gbit/s,the dispersion of the system is serious. with WDM—PON signal rate increased, the dispersion problem is more and more serious,so we do further design base on the original system for10Gbit/s,adding a dispersion compensating optical fiber,the system of transmission indexes have been very good promotion through the experimental eye and Q value contrast, and In order to make further analysis and summary,We change the dispersion compensation fiber and optical cable transmission parameters on WDM—PON system performance. Finally we find a good upgrade solution of passive optical network,by the experiment.