# All-Optical Simultaneous Frequency Metamorphose Contingent on a Three Parallel SOA-MZIs Copula
## 4 Simultaneous Up-Conversion Characterization
The low frequencies of the three input signals are \(f_{1}=0.5\) GHz, \(f_{2}=1\) GHz, and \(f_{3}=1.5\) GHz, the repetition rate of the pulsed signal is \(f_{s}=19.5\) GHz and its harmonics are at \(H_{n}=nf_{s}\). The CG substantiates the veracity and reliability of the theoretical work and its outcomes with the simulation one. In addition, the CGs at \(5/f_{s}+f_{m}\) reach the peak values at the input power of \(-10\) dBm of the low frequency signals. They reached 37, 32.5, and 27 dB at \(-10\) dBm at \(5/f_{s}+f_{1}=98\) GHz, \(5f_{s}+f_{2}=\)98.5 GHz, and \(5f_{s}+f_{3}=99\) GHz, respectively, linked to the fifth harmonic of the control pulsed signal. Therefore, the apical CGs are achieved at \(-10\) dBm for any replica of the high frequency signal at the outer port of the three parallel SOA-MZIs displayed in Figure 4. The augmentation of the input power surmounting \(-10\) dBm leads to degradation of the CGs highly in comparison with the ones at the optical power lower than \(-10\) dBm. Furthermore, the variation in CGs between the frequency shifting up to 98 GHz related to the first data signal and 99 GHz related to the third data signal is 10 dB. The CGs verified in the theoretical and simulated results propound a low-pass behavior, in which the corner frequency ensues at \(f_{c}=\frac{1}{2\pi\tau_{d}}\)[15]. The attributes of the simultaneously high frequency OFDM signals dependent on the three parallel SOA-MZIs system is assessed by measuring the values of the error vector magnitude (EVM) and the bit error rate (BER) parameters [20] at different bit rates. The characteristics of the OFDM data for 64 subcarriers generated by the detection and generation module at the electrical port of each MZM with the 25% cyclic prefix (CP) are demonstrated in [21]. It is important to mention that each subcarrier carries quadrature phase shift keying (QPSK) data. Figure 6 propounds the simulated EVM and BER results of the high frequency signal after mixing at \(5f_{s}+f_{3}=99\) GHz, which are acquired for a variety of bit rates ranging from 0.125 to 2 Gbit/s at the outer port of the three parallel SOA-MZIs link. Figure 6 also displays the dependence of BER on EVM for OFDM modulation that obtains a passable BER equal to \(10^{-3}\) for EVM of 34% at the bit rate of 2 Gbit/s at 99 GHz for simulation results. The EVM and BER values are procured when the optical input power of IF data signals is \(-10\) dBm. Moreover, the exploitation of the forward error correction (FEC) allows for reducing BER values [22]. This analysis is compliant with CG measurements propounded in Figure 5 where the CG of the mixed OFDM signal at \(5f_{s}+f_{3}\) can be approximately evaluated up to 27 dB. Therefore, the decrease in the CG of the up-converted OFDM signal at \(nf_{s}+f_{m}\) leads to augmenting the BER values along with the EVM ones, especially at 99 GHz presented in Figure 6. As a result, the optical conversion system depended on the three parallel SOA-MZIs link induces a very low distortion on  
\[CG_{nf_{s}+f_{1}} = \left|-K\frac{\frac{1}{\tau}\sqrt{\frac{2p_{nf_{s}}}{G_{\text{LNA} }R}}}{1-j\omega_{1}\tau_{d}}\right|^{2} \tag{4}\]0 The theoretical and simulated conversion gains (CGs) of the simultaneous up-converted signal at \(5f_{s}+f_{m}\) as a function of various optical input powers of the low frequency signals. mixed signals, leading to premium performance characterizations of the simultaneous up-conversion system.