A cubic nonlinearity of dye solution can be taken into consideration to study many nonlinear phenomena, such as phase conjugation, holography, amplification [1,2, 5, 6 and 7]. Nonlinear processes strongly depend on intensity and frequency of radiations involved in these processes. A dye solution can be modeled by a typical three-level configuration (S0-S1-S2) , for which the transitions of molecules in principal channel (SO-S1) are realized by the light fields of intensity I12 at frequency ω0. At the same time, light fields with intensity I23 at frequency ω interact with excited molecules to realize their transitions in excited channel (S1-S2). For this model, the conditions of phase response saturation are determined in principal channel. The saturation of phase response of dye solution in principal channel (S0-S1) is realized at saturation intensity I_(12)~(saT) , decreasing with increasing of radiation intensity in excited channel I_(23). The saturation intensity I_(12)~(saT) has its optimum (minimum) values when the frequency of light fields in principal channel is tuned with Stokes shift from the centre of principal absorption band. In addition, the saturation intensity I_(12)~(saT) has its optimum when the radiations in excited channel have enough big intensity I23 and a frequency tuning with anti-Stokes shift from centre of absorption excited band.
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