Analytical modeling and bit sequence impact investigation of XPM-SMZI-induced nonlinear crosstalk in 4 × 4 interconnect

Abstract

This paper presents an analytical model of the origin of nonlinear crosstalk induced by the XPM-SMZI (Cross-Phase Modulation-Symmetric Mach–Zehnder Interferometric) phenomenon occurring in the TWSOA (Traveling Wave Semiconductor Optical Amplifier). We analyze the variation of nonlinear crosstalk with increasing logic levels and length of the input bit sequence. The investigation shows that alteration in high and low logic of bit sequence engenders changes in cross-phase modulation occurring in TWSOA and hence brings nonlinear crosstalk into the picture. The performance is evaluated on 4×4 switching interconnect with a TWSOA cavity length of 500[Formula: see text][Formula: see text]m, a width of 3[Formula: see text][Formula: see text]m, and a height of 0.8[Formula: see text]nm with 0.15[Formula: see text]A injection current in SMZI configuration operating at 10[Formula: see text]Gbps. The performance of the switch is also tested by comparing various combinations of bit logic inputs. The degradation is observed in the quality of service with an increase in the number of ‘1’s in bit sequence. The Extinction Ratio (ER) also deteriorates when a logic ‘1’s appears at consecutive places. This impairment in ER can be controlled by bias conditions of TWSOA. The promising crosstalk of [Formula: see text][Formula: see text]dB has been achieved and is further validated by comparing with previously reported techniques.