Transmission of a 40 GHz optical millimeter wave generated by quadrupling a 10 GHz local oscillator via a Mach-Zehnder modulator

We have experimentally demonstrated the generation of 40GHz optical millimeter (mm) waves with a Mach-Zehnder modulator driven by a 10GHz local oscillator. The generated optical mm wave mainly consists of two tones, positive and negative second-order sidebands. The transmission performance with two signal modulation formats is investigated. According to our theoretical analysis and experimental results, the transmission distance is limited by fiber dispersion because of the time shift of the signal pulse carried by the two tones when the signal is modulated on both sidebands. However, this transmission distance limitation can be eliminated when only one sideband is modulated by the signal since the time shift of the signal pulse is overcome.