Highly efficient four-wave mixing in double-Lambda system in ultraslow propagation regime

摘要

We perform a time-dependent analysis of four-wave mixing (FWM) in a double-Lambda system in an ultraslow-propagation regime and obtain the analytical expressions of pulsed probe laser, FWM-generated pulse, phase shifts and absorption coefficients, group velocities, and FWM efficiency. With these analytical expressions, we show that an efficiently generated FWM field can acquire the same ultraslow group velocity (V-g/csimilar to10(-4)-10(-5)) and pulse shape of a probe pump and that the maximum FWM efficiency is greater than 25%, which is orders of magnitude larger than previous FWM schemes in the ultraslow-propagation regime.