Nested phase modulators for millimeter optical wave signal generation

Applications like radio-over-fiber (RoF) for wireless communications, imaging, radio astronomy investigations, and fifth generation (5G) and beyond communication systems are great candidates for optical production of millimeter-wave (mm-wave) waves. Using nested phase modulators, the optical generation of mm-wave signals is theoretically examined and then simulated. It is mathematically analyzed and discussed how the time-delay between the two nested phase modulators affects the mm-wave signal that is generated. In other words, there are two phase modulators fed with an external cosine radio frequency signal. The first phase modulator is directly connected to the first phase modulator, the second phase modulator is fed with the same radio frequency but after time delay. The OptiSystem 7 software was used to conduct the simulations and produce the results. With less complicated systems, the maximum mm-wave generation that could be achieved was 120 GHz.