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-
