LAUSR

Abstract Photonic generation of background-free microwave waveforms with multi-format and parameter tunability is proposed and demonstrated. In the approach, the polarization division multiplexing Mach–Zehnder modulator (PDM-MZM) is employed to modulate the linearly polarized lightwave. After properly adjusting the modulation indices of the PDM-MZM, background-free square and triangular waveforms will be obtained after heterodyne detection; by driving the polarization modulator with binary sequence, the structure can also generate background-free digital modulation signals, including amplitude shift keying (ASK), phase shift keying (PSK) and frequency shift keying (FSK) signals via the same structure. The approach is investigated by simulations. Square and triangular waveforms with repetition rate of 20 GHz are obtained, and digital modulation signals with modulation rate of 2 Gbit/s are generated. The proposed generator shows flexible tunability of carrier frequency, bit rate and modulation format. The stability of the structure is verified by phase drift, polarization error and RF driven voltage offset.