“…Commonly, different nonlinear optical effects like four wave mixing (FWM), cross phase modulation (XPM), self-phase modulation (SPM), parametric amplification (PA), and cross gain modulation (XGM) arising from the second or third order susceptibility of highly nonlinear fiber (HNLF), periodically poled lithium niobate (PPLN) waveguide or semiconductor optical amplifiers (SOAs) have been used for channel aggregation [10,11,14,19,12,8,27,3,4,6,1]. In [10,11,1] for instance, aggregation of OOK and MPSK signals to a higher bit rate QPSK signals based on XPM using HNLF have been shown. QAM-8 signals have been generated by the aggregation of QPSK and OOK signals using XPM and XGM in SOA [1] and also from BPSK inputs using XPM and PA in HNLF [19,12].…”