Analysis of crosstalk penalty in dense optical chip interconnects using single-mode waveguides

A crosstalk model to analyze the impact of crosstalk on the system parameters is developed. The following light source scenarios are investigated: (1) weakly coherent and uncorrelated, (2) weakly coherent and correlated, and (3) strongly coherent and correlated. Using a 1-dB power penalty criterion at a bit-error-rate of 10^-15, it is shown that the crosstalk between neighboring waveguides must be smaller than -12 dB if the wavelength spacing or the linewidth of the sources is much larger than the receiver bandwidth. In the worst case, where the channels share the same monochromatic light source, the maximum crosstalk level declines to -25 dB. In a practical realization, where the sampling level is not optimized, the allowable crosstalk is reduced to -32 dB