HIGH-ORDER HARMONICS FROM TWO-LEVEL ATOMS IN LASER FIELD WITH LOW-FREQUENCY
低频激光场中二能级原子的高次谐波

This paper derives the equation of motion followed by the induced polarization of the two-level atoms subject to the laser field with frequency much lower than that of the transition between the levels.With the approximate solution to the equation of motion under the conditions of the weak external field and of the ultra-intense one,we obtain the characteristics of the corresponding high-order harmonics from the two-level atoms.