Simulation of Cross Phase Modulation in Intersubband Transition of InGaAs/AlAs/AlAsSb Coupled Quantum Wells Based on Vector Signal Analysis of Electrical Signals

A simple technique is presented for simulating cross phase modulation (XPM) in the intersubband transition of InGaAs/AlAs/AlAsSb coupled quantum wells. To simulate XPM of a CW probe light induced by strong pump pulses, vector signal analysis is performed for equivalent phase-modulated electrical signals whose time scale is expanded by a factor of 4 × 10 7 as compared with the probe light. The proposed technique can be used to efficiently calculate the instantaneous phase and power spectra of the electrical signal while taking account of various conditions in the experiments, from which a quantitative relationship is found between the phase shift and spectral shape. By comparing the measured and simulated spectra, we can accurately evaluate the phase shift of the probe light.