## 6 Challenges  
To strengthen the validity of our proposed all-optical 4-bit parity generator and checker, we have conducted comprehensive simulations using Wolfram Mathematica to verify its performance. Given the constraints of not having access to a physical lab setup, simulation-based validation becomes paramount in assessing the feasibility and functionality of our design. These simulations were meticulously crafted to model the behavior of the CR-SOA-based MZI in the designed configuration, providing insights into its operational characteristics and performance metrics. The results from these simulations demonstrate the system's capability to operate at an impressive speed of 120 Gb/s with high accuracy and reliability. Despite the absence of physical experimentation, our simulation-based approach enables us to assess the system's behavior under various scenarios and conditions, ensuring thorough validation of its functionality. Detailed analysis of key performance metrics, such as BER and QF, not only confirms the efficacy of our design but also provides valuable insights for further optimization and refinement. While physical experimentation would undoubtedly provide additional validation, our reliance on simulation tools showcases the versatility and accessibility of our approach, making it applicable to a wider range of researchers and practitioners in the field. Currently, researchers have developed experimental setups for various optical logic circuits utilizing SOA technology [3; 26; 27; 28; 29; 30; 31; 32; 33]. The CR-SOA-based parity generation and checking schemes offer significant advantages in terms of high-speed data processing, improved modulation bandwidth, and enhanced signal processing capabilities. However, it is crucial to acknowledge the limitations and uncertainties associated with this technology to provide a comprehensive understanding of its scope and applicability. One of the primary limitations of CR-SOAs is their susceptibility to thermal effects. As injection bias currents increase to improve the QF and overall performance, the generated heat can cause thermal saturation, impacting the gain dynamics and carrier lifetime within the CR-SOAs. This thermal sensitivity necessitates efficient thermal management strategies to ensure stable and reliable operation, particularly in high-speed and high-power applications. Another limitation is the inherent noise introduced by ASE. While the carrier reservoir structure helps mitigate the impact of ASE noise, it cannot be eliminated. This noise can degrade the signal quality and QF, especially under conditions of intense ASE. The practical implementation of CR-SOAs must, therefore, carefully balance the ASE noise levels to maintain acceptable performance metrics. The scalability of CR-SOA-based systems also poses challenges. Integrating multiple CR-SOAs into a single chip for complex logic operations requires precise control over each device's parameters and interactions. Variations in manufacturing processes can lead to inconsistencies in performance, affecting the overall reliability and efficiency of the integrated system. Moreover, the current understanding of CR-SOAs is primarily \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Scheme** & \
\begin{tabular}{l} **Pulse** \\ **Modulation** \\ \end{tabular} &
\begin{tabular}{l} **Data Rate** \\ **(Gb/s)** \\ \end{tabular} & **Metric** & **Ref.** \\ \hline \hline SOA: & & & & \\ Parity generator & RZ & 10 & ER = 11.24 dB & [3] \\ Parity checker & RZ & 10 & ER = 8.36 dB & [3] \\ \hline QD-SOA: & & & & \\ Parity generator & RZ & 160 & AM = 0.14 and 0.22 dB & [4] \\ Parity checker & RZ & 160 & AM = 0.05 and 0.21 dB & [4] \\ \hline RSOA: & & & & \\ Parity generator & NRZ & 300 & QF = 19.49 & [5] \\ Parity checker & NRZ & 300 & QF = 21.46 & [5] \\ \hline CR-SOA: & & & & \\ Parity generator & RZ & 120 & QF = 32.72 and 12.35 & \\ Parity checker & RZ & 120 & QF = 35.13 and 15.76 & This work \\ \hline \hline \end{tabular}
\end{table}