Impact of finite extinction ratio of modulator on photonic time-stretch system

In this paper, we discuss the impact of finite extinction ratio of modulator on the photonic time stretch (PTS) system and address concise expressions of all harmonics for modulation with a single arm Mach-Zehnder modulator (MZM) and a push pull MZM separately. The 3dB bandwidth of the system is investigated based on the theoretical analysis. Both experimental and numerical results are presented to verify the correctness of the theoretical model.