Colorless monolithically integrated 120° downconverter.

We numerically demonstrate colorless reception of dense wavelength division multiplexed channels in the C-band for high-order QAM (16-64 QAM) signals on a 120° monolithically integrated downconverter, based on a 2x3 MMI with calibrated analog IQ recovery. It is shown that the proposed calibrated 120° downconverter can increase up to 80 the number of coincident channels in an efficient way, exhibiting good signal dynamic range and high fabrication yield. As this downconverter makes use of the minimum number of power outputs required for perfect recovery of IQ signals, it becomes an interesting alternative to conventional 90° based downconverters.