Optical multiple millimeter-wave signal generation using frequency quadrupling for radio-over-fiber systems

Abstract

In this work, we propose and investigate a novel modulation technique for the generation of multiple millimeter wave (mm-wave) signals using high-order harmonic generation with a dual-electrode Mach-Zehnder modulator (MZM). The laser output is split into two branches by the use of a polarization beam splitter. We use polarization multiplexing to avoid the inter-symbol interference between multiple mm-wave signals. The proposed technique is comprised of two parallel MZMs. As an example, we consider an RF 1 at 7.5 GHz and RF 2 at 8.125 GHz, each of which carries its own data signal and drives each MZM, respectively; and mm-wave signals at 30 GHz and 32.5 GHz, i.e. a frequency quadrupler, are obtained after photomixing. The performance of the system is evaluated in terms of Q-factor. Simulation results show that data signal at 625 Mb/s is successfully transmitted over 50 km of single mode fiber. The generated mm-wave signal is robust to chromatic dispersion.