Origin of channel crosstalk in 100 GHz-spaced silica-based arrayed-waveguide grating multiplexer

It is shown that the channel crosstalk limit of -39 dB for the recently developed 100 GHz-spaced silica-based arrayed-waveguide grating multiplexer is determined by the optical path phase error distribution and that the crosstalk caused by the deformation of the light power distribution in the multiplexer is -39 dB. The high-frequency components of the phase error distribution should be reduced by at least two-thirds to achieve a crosstalk of -39 dB