Optical post chromatic dispersion compensation in an optical fiber communication system.

摘要

Like all communication channels, optical fibers are not ideal media. They have impairments that limit the maximum communication speed they can handle. Driven by the world's growing need for communication bandwidth, progress is constantly being reported in the building of newer fibers capable of handling the rapid increase in traffic. However, building an optical fiber link is a major investment that is very expensive to replace. For example, the optical fiber cables installed during the 1980s consist of more than 50 million kilometers of "standard" single-mode fiber. Since old optical fibers cannot be easily replaced with newer ones, innovative methods of exploiting the available bandwidth are crucial.;A major impairment that restricts the achievement of higher bit rates with standard single mode fiber is chromatic dispersion (CD). This is particularly problematic for systems operating in the 1550 nm band, where the chromatic dispersion limit decreases rapidly in inverse proportion to the square of the bit rate. We opted in effect to compensate the chromatic dispersion using optical techniques, which is only natural to expect, given that CD originates in the optical domain. Nevertheless, electrical equalization exists and can offer the advantages of a lower cost and smaller size through integration within the electronics transceiver. Taking advantage of the Talbot effect (a self-imaging phenomenon that occurs when a periodic signal propagates through a dispersive medium at a given distance named Talbot distance) in the regeneration of a periodic signal where one period is similar to the initial transmitted signal, we propose a new technique that mitigates the signal at the receiver. Our solution is extended to the combination of second and third order chromatic dispersion. These can be handled either separately or simultaneously by our TEChDC technique. Then, we assess the performance of the TEChDC scheme under realistic transmission impairments. To prove the feasibility of the TEChDC architecture, an applet was created to simulate all possible conditions including second and third order dispersion. The simulation results show that the TEChDC method is capable of carrying enormous data through long distance.