Abstract
We successfully observed the nonlinear eight-wave mixing (EWM) signal via one electromagnetically induced transparency (EIT) window and double optical pumping channels in an open five-level atomic system of 87Rb. By carefully controlling the arrangement of the incident laser beams, the corresponding four-wave mixing (FWM), six-wave mixing (SWM) and EWM signals can be made to coexist with similar signal amplitudes and transmit through the same EIT window in such open five-level atomic system.