Characteristics of ionization probability with adiabatic inversion by stochastic fields
Shuichi Hasegawa, Hitoshi Maeda, Takafumi Kakudoh +1 more
Adiabatic inversion in two- and three-level systems excited by stochastic fields is investigated. The stochastic electric fields, which are called the chaotic field and the phase-diffusion field, can invert the population of a two-level atom. In a three-level system, we compare the method of sweeping the laser frequency with that of the resonance excitation by lasers that have bandwidths appropriate to the width of Doppler broadening. When the Doppler shift is taken into account, bandwidths of the electric fields are effective to ionize atoms efficiently. When sweeping the first exciting laser frequency, the delay of the second laser pulse increases the ionization probability. If the half width at half maximum of Doppler broadening is narrow and two lasers irradiate atoms simultaneously, the finite bandwidths of the lasers ionize more atoms than sweeping the laser frequency. On the other hand, if the Doppler broadening is large or the second laser irradiates the atoms properly after the first laser, sweeping the first laser frequency is efficient for ionization. Sweeping the laser frequency is not suitable for the system where the intermediate state's spontaneous-decay constant is short. For that system it is efficient to ionize the atoms by lasers that have the finite bandwidth appropriate for the Doppler broadening.
Physical Review A•Apr 1, 1992•5 citations