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 he reduced as well. The maximum tolerable component crosstalk for a network with arbitrary size is reduced to -30 dB