Large-Signal Operation of a Semiconductor Optical Amplifier as a Phase-Shifting Element for Microwave Signals

We investigate the modulation index dependence of the phase shift experienced by a sinusoidal microwave signal carried by an optical carrier and propagating through a semiconductor optical amplifier. We show that for large modulation depths, simple small-signal nonlinear models fail to predict the measured phase shift and we present a large-signal model that fits the experiments well.