Research on 60 GHz optical millimeter-wave over fiber system using two cascaded Mach-Zehnder modulators

A frequency sexualizing technique for the generation of millimeter-wave (mm-wave) is proposed and investigated. The proposed technique is comprised of two cascaded dual-electrode Mach-Zehnder modulators (MZMs). The first MZM, biased at minimum transmission, is only used for optical carrier suppression modulation, and the second MZM, biased at maximum transmission, is used for both even-order optical harmonic generation and data signal modulation. From the theoretical analysis and simulated demonstrations, it is concluded that using an RF signal at 10 GHz, which carries the data signal and drives the MZMs, an mm-wave signal at 60 GHz can be obtained. The power penalty is less than 1 dBm after 50 km SMF transmission, mostly because of the higher optical harmonic distortion suppression ratio (OHDSR).