Photonic generation of millimeter-waves using two cascaded Electro-Absorption Modulators in radio-over-fiber systems

We propose a novel photonic millimeter-wave (mm-wave) generation technique using two cascaded Electro-Absorption Modulators (EAMs). The two cascaded EAMs are driven by the same low radio frequency (RF) signal but with certain phase shift to suppress odd-order optical sidebands and enhance second order sidebands to obtain frequency doubling and quadrupling. It is shown that RF modulation voltage, phase shift between the two EAMs, and their bias voltages are the keys to be adjusted to efficiently generate high quality mm-wave signal. Experimental proof of concept is also demonstrated.