Numerical study of large cross-phase modulation with stationary light pulses

We report a systematic investigation of cross-phase modulation using techniques of light storage (LS) and stationary light pulse (SLP) based on the effect of electromagnetically induced transparency. Two light fields are stopped in the medium to prolong the interaction time, which enhances the efficiency of optical nonlinearity. We numerically study the properties of the signal SLP field such as lifetime, light pulse storage efficiency, and stored peak intensity as functions of optical density (OD) and coupling field intensity. The strong nonlinearity between LS and SLP photons leads to a phase shift of up to pi at the single-photon level. Meanwhile, both the LS and SLP photons maintain energy transmission higher than 20%, as the OD of the SLP subsystem is larger than 700. The energy transmission and phase shift can be further improved by increasing the OD of the medium. The performance of the quantum phase gate between two single photons is expected by applying such strong photon interaction. (C) 2021 Optical Society of America