Chirp Characteristics of Silicon Mach–Zehnder Modulator Under Small-Signal Modulation

Chirp characteristics of Silicon Mach-Zehnder Interferometer (MZI) modulators with forward-biased p-i-n and reverse-biased p-n structures are investigated by performing small-signal simulation, respectively. Simulation result shows that the chirp parameter is negative and influenced by the carrier absorption effect, the amplitude, and the frequency of applied sinusoidal modulating signals. Chirp performance at 10 GHz modulation frequency can be obtained by utilizing p-n depletion mode structure. Finally, a way to further lower the absolute value of the chirp parameter is provided by operating the MZI in a push-pull configuration.