Influence of relative phase between probe and driving fields(Φ) Oil propagation effect of a Doppler broadened quasi-Λ type four-level atomic system with spontaneously generated coherence(SGC) is numerically studied.It is shown that by choosingΦ, we can obtain greater GWI and longer propagation distance where GWI exists and hence obtain higher LWI intensity.Doppler broadening width and propagation directions of probe and driving fields have considerable effect on phase·dependent spatial evolutions of GWI and LWI intensity.

Effects of pulse width on ultrahort laser pulse and spectrum and their carrier-envelope phase(CEP)dependence in a dense V-type three-level atomic medium are investigated with numerical solutions of a full Maxwell-Bloch equation without slowly varying envelope and rotating wave approximations.It is shown that:As pulse width is small,pulse splitting number is less,spectrum is wide,high-frequency part of the spectrum is significant,CEP has great effect on pulse and spectrum,particularly effect on time interval between sub-pulses and strength of high-frequency part is more obvious;As pulse width increasing,pulse splitting number increases,width of spectrum narrows and high-frequency part of the spectrum decreases gradually,effect of CEP on pulse and spectrum weakens gradually.