Linearized Frequency Doubling for Microwave Photonics Links Using Integrated Parallel Mach–Zehnder Modulator

In microwave photonics links (MPLs), the multicarrier microwave signals are subjected to intermodulation distortion (IMD) and degrades the linearity of the MPL significantly. A linearization scheme is presented with an integrated parallel Mach-Zehnder modulator (MZM), without requiring optical/electrical filters and optical delays. In addition, to reduce the requirements on the electrical and optical components for the high-frequency applications, frequency doubling is designed in this linearization scheme. Theoretical expressions are presented to analyze this scheme. Experimental and numerical results show that the main IMD2 products are suppressed by more than 35 dB.