Sextuple-frequency two-tone signal generation using two cascaded Mach-Zehnder modulators for multiple harmonics cancelling

Abstract

We propose a novel sextuple-frequency two-tone signal generation method using two cascaded Mach-Zehnder modulators (MZMs). The first MZM is used to generate a large third-order harmonics component with a large RF input of 4.64V_π (peak-to-peak). The second MZM is used to suppress first- and fifth-order unwanted harmonics at the same time. The proposed method was investigated by numerical simulations and experiments. We successfully suppressed the unwanted harmonics to less than -21 dB of the intended third-order harmonics by using two MZMs with extinction ratios of 23 dB and 26 dB.