An approach to reduce four-wave mixing effect on existing G.653 fibers for WDM applications

Four-wave mixing (FWM) is a dominant non-linear effect present in wavelength division multiplexing (WDM) networks employing dispersion shifted fiber (i.e., G.653 compliant fiber). To reduce the number of FWM components generated, unequally spaced channel allocation scheme is used. However, it results in increased bandwidth. To overcome this problem, modified periodically unequally spaced channel allocation (PUSCA) scheme can be used which results in fewer FWM components and efficient bandwidth utilization. To further reduce the number of FWM components, paired PUSCA method can be employed. In this paper, a comparative study of both the methods has been made. A figure of merit, defined as the ratio of increase in weighted average signal to FWM noise ratio to increase in bandwidth for a given scheme has been used as a metric of performance. Further, the performance of paired PUSCA scheme on G.653 fiber has been compared with equally spaced channel allocation (ESCA) scheme on G.652 fiber in which FWM is not a dominant non-linear effect. It has been observed that paired PUSCA on G.653 fiber performs better than ESCA on G.652 fiber when the number of channels is less than 30