Development of SOA-MZI based logic gates and all-photonics flip flop

Abstract

Photonics logic gates are actually logic gates that performs various logical functions such as AND, OR and NOT but instead of using electrons, they operate on using light as the main mechanism. XOR logic gates are commonly consist of various components such as optical amplifiers and couplers. These XOR logic gates also apply some of the optical nonlinear effects such as the Cross Gain Modulation (XGM) and Cross Phase Modulation (XPM) as their main operations. Three XOR photonics logic gate configurations (XOR TOAD, XOR SOA-MZI XPM and XOR SOAXGM) are analysed and compared in terms of generated power, optical signal-to-noise ratio (OSNR) and Bit Error Rate (BER). The highest generated power is recorded by XOR TOAD at 23.5 dBm. The XOR SOA-MZI XPM yields the highest OSNR with 109.6 dB and the best BER is observed in the XOR SOA-MZI XGM with the value of 4.42 x 10-22. Eye diagram pattern wise, XOR TOAD showed the widest eye compared to others. All optical flip-flop is also performed in this work which perceived 12 number of ON states with output power of 0.75 mW at 20 Gbps. Whereas at 10 Gbps, there are only 6 ON states with output power of 2.2 mW. This deduces that running at a faster data rate will yield a higher number of ON states but having lower output power. Four SOA-MZI logic gates configurations AND, NOR, OR and NAND are compared in terms of output power. The AND and the NOR SOA-MZI logic gates depicted low output power of 1.220 dBm and 2.446 dBm, respectively. While the OR and the NAND SOA-MZI logic gates demonstrated high output power of 21.738 dBm and 21.018 dBm, respectively. In summary, the XOR SOA-MZI XGM commemorated the best performance among other XOR logic gate setups since it has moderate values of generated power and OSNR, high BER value and comprehensive eye diagram pattern, which concludes minimum noise in the configuration. In all optical flip-flop observation, the higher data rate yields double ON states output but low output power. Finally, in the SOA-MZI logic gates utilizing two SOAs in the arrangement, the output power is small due to the limiting effect by the SOA’s saturation.