###### Abstract  
This article presents an analysis of an electro-optical up-converter relying on a semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI). The pulsed control signal is generated by an optical pulse clock (OPC) with a repetition rate of \(f_{s}=19.5\) GHz. The intermediate frequency (IF) signal, which carries the modulation format known as quadratic phase shift keying (QPSK) at a frequency \(f_{IF}\), is shifted at the output of the SOA-MZI to high outlet mixing frequencies \(nf_{s}\pm f_{IF}\), where \(n\) represents the harmonic order of the OPC. To examine the characteristics of the sampled QPSK signals, we employ the Virtual Photonics Inc. (VPI) emulator and evaluate them using significate metrics like error vector magnitudes (EVMs), conversion gains, and bit error rates (BERs). The up-mixing process is mainly achieved through the cross-phase modulation (XPM) effect in the SOA-MZI, which operates within a 195.5 GHz ultrahigh frequency (UHF). The electro-optical SOA-MZI up-converter demonstrates consistent uplifting conversion gains across the scope of the output mixing frequencies. The simulated conversion gain deteriorates from 38 dB at 20 GHz to 13 dB at 195.5 GHz. The operational efficiency of the electro-optical SOA-MZI design, employing the standard modulation approach, is also evaluated by measuring the EVM values. The EVM attains a 24% performance level at a data rate of 5 Gbit/s in conjunction with the UHF of 195.5 GHz. To corroborate our results, we compare them with real-world experiments conducted with the UHF of 59 GHz. The maximum frequency range of 1 THz is attained by increasing the OPC repetition rate. Ultimately, through elevating the control frequency to 100 GHz, the generation of terahertz replicas of the 4096-QAM (quadrature amplitude modulation) compound signal becomes achievable at heightened UHF, extending 1 THz, while maintaining a data transmission rate of 120 Gbit/s and upholding exceptional performance characteristics. electro-optical up-mixing; standard modulation topology; semiconductor optical amplifier Mach-Zehnder interferometer; quadrature amplitude modulation  
To achieve this, various types of mixers can be employed, including electrical, optical, or electro-optical mixers. Numerous methods can be used for photonic signal up-conversion, utilizing mixing processors, including an electro-optic modulator (EOM) [7; 8], an electro-absorption modulator (EAM) [9] that can be used as an up-converter [10], and a photodiode (PD) [11; 12]. Moreover, a range of all-optical frequency transformation techniques [13; 14; 15; 16] capitalizes on the nonlinear attributes of an efficient semiconductor optical amplifier (SOA). For the employment of a SOA-MZI (SOA-Mach-Zehnder interferometer), the nonlinear cross-phase modulation (XPM) mechanism is employed for the up-conversion [17; 18], and to complete the duplex purposes, both up- and down-conversions can be achieved [19]. Photonic transmission technologies also offer options for frequency mixing through sampling techniques [20; 21; 22; 23]. SOA-MZIs can also be used for the gate functions [24; 25] in the ripple carry adder design [26]. All-optical mixing is achieved in these various concepts due to the nonlinear characteristics of the mixers. To achieve mixing, another approach consists of manipulating the SOA electrical port. Two scenarios are applied: the standard modulation scenario, involving only one branch of the SOA-MZI; or the differential modulation scenario, involving both branches of the employed SOA-MZI. In the photonic standard SOA-MZI modulation, the carrier density of the top SOA is modified, whereas in the photonic differential SOA-MZI modulation, the carrier densities of the upper and lower SOAs are altered. As a result, changes in carrier density also modulate the photonic gain. The sampling and the IF or RF signals, requiring up- or down-conversion, can both be processed simultaneously on the same device [27; 28].