Saturation in the principal (excited) channel of four-level medium as an effective two-level configuration

Saturation of complex molecules affects the nonlinear processes occurring in medium. The medium can be described by two-, three-, and four-level configurations. principal singlet-singlet excited triplet-triplet channels a four-level, N-type, configuration were used to study medium, which was radiation with two frequencies. Under weak population energy levels channel (a small ratio total probability spontaneous irradiate transitions for both p 23 / 31 ), (singlet-singlet) is similar two-level configuration. At same time, effective (the large intensity high) makes (triplet-triplet) coincide saturation (excited) channel, as configuration, this controlled external acting on (principal) channel. Finally, average excitation into (ratio 23/ ≈ 1) three-level level result combination between second singlet S 2 first triplet T 1 .