Crosstalk modeling and analysis of FBG - OC - based bidirectional optical cross connects in a WDM network

Abstract

Bidirectional optical cross connects (BOXCs) using a fiber Bragg gratings (FBGs) and optical circulators (OCs) have been considered for bidirectional wavelength division multiplexing (WDM) ring networks. Theoretical analysis is carried out to evaluate the performance of BOXCs in a WDM transmission system in the presence of intraband crosstalk due to FBGs. The analytical expression of in-band crosstalk due to FBG-based BOXCs is developed. The expression of BER and power penalty is derived considering the effect of in-band crosstalk for the operation BOXC in a WDM system. Analysis is also extended considering the impact of amplified spontaneous emission (ASE) noise due to optical amplifier used in a WDM ring network. We analyzed here two configurations of FBG-based bidirectional optical cross connects: 2 x 2 BOXC and 4 x 4 BOXC for bidirectional WDM ring networks and evaluate the bit-error-rate (BER) and power penalty (PP) of these configurations. It is found that the BER and PP, due to linear homodyne crosstalk induced by FBGs, both are increased with the number of wavelength channels increased for both bar and cross state of BOXCs. BER and PP are not affected with the position of the wavelength channels in the bar state while in the cross state, if the position of the wavelength channels is increased, the BER and PP both are increased. Performance degradation in terms of BER and PP due to BOXC induced crosstalk and also due to the effect of ASE noise is evaluated and optimum system design parameters are determined for operation ofWDM network at BER of 10-