Generation of Frequency-Multiplied and Phase-Coded Signal Using an Optical Polarization Division Multiplexing Modulator

A novel method to generate frequency-multiplied and phase-coded microwave signals based on a polarization division multiplexing (PDM) dual-arm Mach-Zehnder modulator (DMZM) or a PDM dual-parallel MZM (DPMZM) is proposed. In the proposed scheme, the PDM-DMZM or PDM-DPMZM is employed to produce two orthogonally polarized wavelengths with a wavelength spacing that is two, four, or eight times of the driving frequency. Then the signal is sent into a polarization modulator-based microwave photonic phase coder for phase coding. A theoretical analysis and an experiment are carried out. Phase-coded signals with frequency multiplication factors of two, four and eight are successfully generated. The bandwidth of the system is discussed, and the impact of the polarization extinction ratio is also analyzed.