Nonlinear phase matching in parametric four-wave mixing process of Cs vapor

Abstract Phase matching plays an important role on the nonlinear process. The linear phase matching in parametric four-wave mixing (FWM) process of Cs vapor is firstly studied and we find out that linear phase matching can be implemented within narrow range of frequency offsets for involved pumping light. Considering the high pumping power intensity, we innovatively take the influence of nonlinear refractive index to phase matching into account. The relationship between threshold pump intensity and frequency offsets is discovered, and it makes up a complicated curved surface. The threshold has the minimum value when the frequency offset satisfies the condition of v1 + v2 = 0. In addition, these simulation results could provide support for further study and pumping parameters selection in FWM process of Cs vapor.