Figure 2
(a1)–(a3) The nested FWM signal spectra when scan \(\Delta_{1}\). (a1) With \(\Delta_{5} /\Gamma_{20} = { - }50\). (a2) With \(\Delta_{5} /\Gamma_{20} = 0\) (a3) With \(\Delta_{5} /\Gamma_{20} = 50\). (b1)–(b3) Intracavity dispersion curves (solid curves), absorption curves (dashed curves), and detuning \(\Delta_{1}\) lines (dotted lines), corresponding to (a1)–(a3). (c1)–(c3) The dressed five-energy levels diagram, corresponding to (a1)–(a3). (a4)–(a6) The cascaded FWM signal spectra when scan \(\Delta_{1}\). (a4) With \(\Delta_{3} /\Gamma {}_{20} = { - }50\) (a5) With \(\Delta_{3} /\Gamma_{20} = 0\). (a6) With \(\Delta_{3} /\Gamma_{20} = 50\). (b4)–(b6) Intracavity dispersion and absorption curves corresponding to (a4)–(a6). (c4)–(c6) The dressed five-energy levels diagram, corresponding to (a1)–(a4). The other parameters are \(G_{2} = 50\,{\text{MHz}}\), \(G_{3} = 50\,{\text{MHz}}\), \(G_{5} = 50\,{\text{MHz}}\), \(\Delta_{2} = 0\,{\text{MHz}}\) and \(\Delta_{ac} = 0\,{\text{MHz}}\).
