Analysis of Crosstalk Penalty in Dense Optical Chip Interconnects Using Single-Mode Waveguides

The maximum allowable crosstalk among adjacent channels in a single-mode waveguide array is an important parameter in determining the minimum waveguide spacing in a high-density optical chip-to-chip interconnect system. In this paper, a crosstalk model is developed to analyze the impact of crosstalk on the system performance. The following light source scenarios are investigated: 1) noncoinciding and uncorrelated, 2) coinciding and uncorrelated, and 3) coinciding 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 requirement to the crosstalk level is further reduced to -32 dB. © 1991 IEEE