Highly selective four-wave mixing of low-intensity radiation in a degenerate tow-level atomic system

摘要

Quasi-degenerate four-wave mixing (FWM) of low-intensity radiation (with an intensity less than 1 mW cm~-2) was observed for the 5 S_1/2(F=2)-5P_3/2(F'=3) transition in an optically transparent ~87Rb vapour under conditions of electromagentically induced absorption. The efficiency of frequency conversion was no less than 1 /100 with respect to the intensity of pump waves. Nonlinear FWM is highly selective relative to the frequency detuning of pump waves (the FWM full width at half maximum was less than 50 kHz).