# All-Optical Simultaneous Frequency Metamorphose Contingent on a Three Parallel SOA-MZIs Copula
## 2 Practicability of Frequency Mixing Dependent on an Optical Three Parallel SOA-MZIs Linkage  
The two parallel SOA-MZIs technique was already interpreted for all-optical multiple logic gates in [16, 17] and for wavelength conversion in [7, 8, 9, 10, 11]. The main novelty in the present assignment lies in applying a sampling approach in the three parallel SOA-MZIs link to attain simultaneous mixing to higher frequencies with excellent efficacy of the optical three parallel SOA-MZIs system. The up and down frequency conversion processes depending on a cascaded SOA-MZIs relation were achieved in [12]. In addition, the simultaneous two intermediate frequency (IF) signals that are up-converted at the outer port of a monocular sampling SOA-MZI are performed in [13]. The schematic diagram of the used SOA-MZI in simulations and the SOA-MZI static and dynamic merits are demonstrated in [14]. The proposed system dependent on the sampling SOA-MZIs connected in parallel employing standard modulation mode corresponds to a novel system to achieve mixing to higher frequencies. This unprecedented system relied on a cross-phase modulation (XPM) of input control and data signals in the MZI created by utilizing SOAs for each SOA-MZI as seen in Figure 1. In this architecture, for each SOA-MZI, the inward signal is placed in the topmost SOA through the upper port (UP). In addition, the optical pulsed signal at a sampling frequency \(f_{s}\), at the wavelength \(\lambda_{s}\) is entered to the middle port (MP) input and then it is split into two equal signals, which are passed through supernormal and inferior arms jointly by plying an optical coupler (OC). The explanation of the operation of sampling methods through each SOA-MZI is the same and was already clarified in [12, 13, 14, 15]. Therefore, the output signals after shifting are effectuated at the external port of each SOA-MZI. These shifted signals are well upgraded at the outer port of SOA-MZIs thanks to enhancing the quality of the optical pulsed signal, where its harmonics have higher power levels particularly at higher harmonic rank \(n\). As we can monitor from the output spectrum of the shifted signal that is identified after optical filtering adjusted at \(\lambda_{s}\) in Figure 2A, the low frequency signal at \(f_{1}\) is shifted to the high frequency signal at \(nf_{s}\pm f_{1}\) due to the sampling operation, where \(n\) corresponds to the order of pulsed signal harmonics. In addition, \(n\) is an integer that extends from 1 to 5 in our investigation since the quality of the sampled signal degrades considerably with the augmentation of \(n\). Furthermore, the second low frequency signal at \(f_{2}\) is mixed at \(nf_{s}\pm f_{2}\) at the SOA-MZI2 output as displayed in the electrical spectrum in Figure 2B, and the third signal is up-converted from \(f_{3}\) to \(nf_{s}\pm f_{3}\) at the SOA-MZI3 output as illustrated in Figure 2C. Consequently, these radio frequency (RF) signals at the extrinsic port of the SOA-MZIs are integrated through an OC to accomplish simultaneous up-conversion at distinct facsimiles at \(nf_{s}\pm f_{m}\), as provided in the electrical spectrum in Figure 2D. Figure 1: Mixing concept dependent on the three parallel SOA-MZIs in the standard modulation mode. OC: Optical Coupler, UP: Upper Port, and MP: Middle Port. A is the mixed signal at the SOA-MZI1 output, B is the mixed signal at the SOA-MZI2 output, C is the mixed signal at the SOA-MZI3 output, and D is the simultaneous mixed signal after combination. This prestigious approach can be drawn in plenty of optical transmission systems, such as on wireless communication networks, radio over fiber (RoF) networks, and millimeter (mm) wave systems as the approaches assumed from a monosyllabic SOA-MZI and a cascaded SOA-MZIs connection [12, 13, 14]. The novel system based on the sampling SOA-MZIs connected in parallel entices many avenues for wideband frequency networks and satellite and radar systems due to its significant profits achieved in this disquisition.