Crosstalk and interference penalty in all-optical networks using static wavelength routers

The crosstalk and interference penalty in an all-optical network using static wavelength routers is analyzed in this paper. A worst case methodology is used to derive the upper bound of the penalty. We show that the penalty strongly depends on the linewidth of the laser source. Up to -20 dB in crosstalk can be tolerated in a moderate-size network (≈105 nodes), with the ratio of the laser linewidth to the electrical bandwidth less than or equal to unity. Larger linewidth has the advantage of reducing the power penalty incurred by phase-to-amplitude noise conversion. However, the number of wavelength channels will be reduced as well. The maximum tolerable component crosstalk for a network with arbitrary size is reduced to -30 dB.