Analysis of crosstalk due to unidirectional and bidirectional optical cross-connects in a WDM network

Abstract

A theoretical analysis is presented to find the impact of crosstalk due to optical cross-connects (aXCs) in a WDM network. An N x N AWG based axc is first considered with one wavelength per channeL Thereafter, a mux/demux based axc with N number of channels and M number of wavelengths per channel isinvestigated. The analytical expressions of in-band and out-band(inter-band) crosstalks due to these axcs are developed. The expression for BER is derived considering the effect of in-band and inter-band crosstalk together for unidirectional operation of an axc in a WDM system. Analysis is also extended to bidirectional axc in a WDM network considering the impact of crosstalk and backscattering. Performance results are evaluated numerically considering M-channel WDM system with N x N axc operating at a bit rate of 10 Gb/s with several system parameters. Performance degradation in terms of BER and power penalty due to axc induced crosstalk is evaluated and optimum system design parameters are determined for operation of a bit rate of 10 Gb/s and BER of 10-9. The results will find application in designing a multiwavelength WDM optical transport network.