Multi-Dressing Four-Wave Mixing Processes in Confined and Non-confined Atomic System

Abstract

Other than generating various four-wave mixing (FWM) processes, multilevel atomic system can also be used to generate co-existing FWM and sixwave mixing (SWM) processes with specially-designed spatial patterns and phase-watching conditions for laser beams. Making use of electro magnetically induced transparency (EIT) windows, and induced atomic coherence, the FWM and SWM signals can be made to be very efficient and pass through the dense atomic medium. When the relative phase between different multiwave mixing processes is tuned, frequency, spatial, and temporal interferences can occur between two different wave-mixing processes. In such cases, FWM and SWM signals are modulated with the phase difference. In this chapter, using phase-control between FWM and SWM channels in a four-level atomic system, we describe temporal and spatial interference between these two high-order nonlinear optical processes. Efficient and co-existing FWM and SWM signals are produced in the same EIT window via atomic coherence. On the other hand, we present the interplay between FWM, SWM, and eight-wave mixing (EWM) resulting from atomic coherence in multi-level atomic systems. FWM with three kinds of dual-dressed schemes (nested, sequential, and parallel schemes), SWM with the quadruply nested dressed, and EWM with the parallel combination of two nested dressed schemes coexisting synchronously in a multi-dressed EIT system were well described. At last, we also investigated the coexisting FWM, SWM and EWM in ultra-thin, micrometer and long cells. Investigations of these multi-dressing schemes and interactions are very useful to understand and control the generated high-order nonlinear optical signals.