Analysis of the efficiency of isotopically selective laser excitation of potassium atoms

A numerical study is made of the interaction of laser radiation with different isotopic forms of potassium, $^{39}$K and $^{40}$K, for time intervals shorter than the relaxation times. The quantum efficiency and selectivity of the process are determined. The behavior of the atoms is considered using the Schrodinger equations for the probability amplitudes. Account is taken of the effects associated with hyperfine splitting of the levels, their degeneracy, and the Doppler effect. Excitation by a single traveling wave and by two oppositely traveling waves is considered and the excitation characteristics of the two regimes are compared.