As known a spontaneously emitted optical line may be splitted by an incident resonant laser radiation. The line shape of the resulting doublet is calculated in dependence on the relaxation constants and on the beam intensity. Furthermore there is a remarkable dependence on the initial state. The line shape may be interpreted as the result of the interference of two LORENTZ lines. Appropriate intensity of the incident beam gives rise to a GOLDBERGER-WATSON double pole.