A novel scheme for high-quality 120 GHz optical millimeter-wave generation without optical filter

•A filterless frequency 12-tupling mm-wave generation using two nested MZMs is presented.•120 GHz mm-wave with OSSR exceeds 37 dB can be generated with low complexity and cost.•An integrated expression for the output of MZM involving several non-ideal factors is given.•The effect of imperfect MZM parameters on the performance of mm-wave is analyzed.

A novel scheme to generate 120 GHz millimeter (mm)-wave from 10 GHz radio frequency (RF) local oscillator (LO) with an integrated nested Mach–Zehnder modulator (MZM) is proposed and demonstrated. By properly adjusting the modulator dc bias voltages and the LO voltages and phases, a frequency of 12-tupling optical mm-wave with an optical sideband suppression ratio (OSSR) higher than 37 dB can be generated without optical filter. This scheme largely reduces the response frequency of the modulator and the LO frequency. Furthermore, the non-ideal nested MZM parameters are analyzed theoretically, and we find that both the imperfect extinction ratio of the MZM and the phase imbalance between two arms of optical coupler have an influence on the performance of the generated optical mm-wave.