Scalability of optical multiwavelength switching networks: crosstalk analysis

An Improved All-Fiber Cross-Connect Node for Future Optical Transport Networks

“…The modularity of such OXNs can be classified according to the ease in which new fiber links (link modularity or L-Mod) or wavelengths (wavelength modularity or λ-Mod) can be added without sacrificing any existing OXN components [4]. Unfortunately, the increase in OXN size further accentuates the detrimental effects of module imperfections on the signals they handle [13]. Furthermore, there is an expected deterioration in node dependability (availability performance and its influencing factors) and increased running costs that limits the potential returns on the investment of added OXN components [34].…”

“…3d) was proposed by Bilodeau et al [10], which pro- vides narrower passbands compared to plain FBGs, but has poor crosstalk isolation X = 20 dB for 100 GHz spacing). Alternative fiber interferometer filtering configurations, namely the Sagnac loops [11] or Mach-Zehnder interferometers (MZI) [12] also fall short of the crosstalk isolation requirements (X ≥ 30 dB) for the current generation of dense WDM systems [13]. Kewitsch et al [14] propose an asymmetric or null coupling filter with an FBG inscribed on its waist as illustrated in Fig.…”

Evaluation of intraband crosstalk in an FBG-OC-based optical cross connect

“…The former, which falls within the signal wavelength slot as shown in Fig.1, cannot be simply eliminated by filtering and results in unacceptable signal degradation. Crosstalk analyses of OXCs presented so far are generally focused on conventional OXCs [2,3]. Tunable FBG based devices present a promising alternative [4,5], however, there has been no crosstalk modeling of this type of OXC in the literature.…”

Photonic Integrated Semiconductor Optical Amplifier Switch Circuits

“…Coherent crosstalk with long timescale fluctuations compromises threshold setting in receivers. The resulting beat noise incurs large power penalties and bit error floors (Gillner et al, 1999). If the path length differences are minimised to less than one bit period and the wavelengths are stable, as might be anticipated in a monolithic multistage network, phase difference becomes invariant and less problematic (Dods et al, 1997).…”

“…Inter-wavelength crosstalk has been studied across architectures. Many early switch architectures assumed one wavelength per switch element in multiwavelength fabrics, and this called for a multi-domain description of spatially-and spectrally-originating crosstalk (Gillner et al, 1999;Zhou et al, 1994;Zhou et al, 1996). Recent requirements for massive data capacities have led recent work to focus on multi-wavelength routing where interwavelength crosstalk can occur through cross gain modulation (Oberg & Olsson, 1988;Inoue, 1989;Summerfield & Tucker, 1999).…”