Influence of Power Distribution on Performance of Intermodulation Distortion Suppression

A linearized analog photonic link based on a dual parallel Mach-Zehnder modulator (MZM) and an unsymmetrical power divider is proposed and demonstrated. By adjusting power distribution ratio of radio frequency signals, the third-order intermodulation distortion (IMD3) of two submodulators balances each other. Influence of power distribution ratio on the performance of IMD3 suppression is evaluated in experiment. When the power distribution ratio is 0.1, IMD3 suppression can achieve to ~ 62.1 dB according to the experimental results. Spurious-free dynamic range is improved by 23 dB in a 1-Hz bandwidth comparing with the scheme based on a single MZM. Experiment results are in good agreement with the theoretical analysis.