Simultaneous Up-Conversion Based on a Co- & Counter-Directions SOA-MZI Sampling Mixer with Standard & Differential Modulation Modes

Abstract

Simulation and experimental performance analyses of simultaneous up-converted signals, for the first time, were investigated utilizing a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) sampling mixer in co- and counter-directions for standard and differential modulation modes. An optical pulse source at a sampling frequency of fs = 15.6 GHz was used as a sampling signal. The IF signal channels carrying quadrature phase shift keying (QPSK) data at frequencies fm were up-converted at different mixing frequencies up to 195.5 GHz. Using the Virtual Photonics Inc. (VPI) simulator, we realized mixed QPSK signals and studied their characteristics through a conversion gain and an error vector magnitude (EVM). Simulations of up mixing operated in a frequency range up to 158 GHz. For the standard modulation in the co-direction, the conversion gain decreased from 43.3 dB at the mixing frequency of 16.6 GHz to 21.8 dB at 157 GHz for the first channel and from 43 dB at 17.6 GHz to 21 dB at 158 GHz for the second channel. The use of the differential modulation principle improved the conversion gain by about 10 dB at 195.5 GHz compared to standard modulations in co- and counter-directions. The EVM reached, respectively, 15.5 and 17.5% for the differential modulation in both configurations, at the bit rate of 100 Gbit/s at 195.5 GHz. The benefit provided by the differential modulation was that EVM values were shifted by 20% for all channels in both configurations at 100 Gbit/s. In the real measurement, we confirmed that co-directional conversion exhibited a better performance than the counter-directional operation. In addition, the real mixed signal exhibited lower efficiency and quality in comparison with simulated signals due to the sensitivity of the receiver.

Establishment of an Electro-Optical Mixing Design on a Photonic SOA-MZI Using a Differential Modulation Arrangement

“…SOA-MZIs are a superb candidate for up and down frequency mixing [32][33][34][35][36][37][38][39][40] due to their exceptional performance with single, cascaded, and parallel SOA-MZIs linkages, including their high frequency conversion range, high data transmission rate, and lofty conversion gain in both empirical and simulated considerations. The used SOA-MZI can be used for high-performance all-optical mixing or electro-optical mixing [41][42][43][44] by combining it with an optical pulse source (OPS) [45][46][47].…”

SOA-MZI Differential Transformation Approach Applied on Simultaneous Electro-Optical Mixing

“…Due to their exceptional ability to display outstanding implementation, such as a high-frequency range, a high data transmission rate, and lofty conversion gains (CGs), SOA-MZIs have a remarkable apparatus for frequency transformation based on monocular, cascaded, and parallel arrangements [32][33][34][35][36][37][38][39][40]. The SOA-MZI can be incorporated with an optical pulse source (OPS) [41][42][43] that employs a mode-locked laser to create an optical pulse train with a very short duration determined in the picosecond (ps) of pulse width and a high repetition rate.…”