Effective excitation method of a three-level medium in a selective photoionization

Abstract

A principle for the e%cient excitation of a three-level medium in a selective photoionization method is examined. It is shown that with special detunings for a given set of the laser-atom interaction the third-level population can be maximized. The expression of the optimal detunings is derived near the two-photon resonance region. It is shown that if the optimal detuning method is applied to three-level systems of Yb and Ca, the first-level populations are inverted to their corresponding third levels by about 100% and 86%, respectively. Application of this method to a Doppler-broadened medium is discussed and it is found that the optimal detuning method with counterpropagating waves will be very effective for selective ionization of wanted atoms.PACS number(s): 32.80.Fb, 32.80.8x

Energy efficient method for two-photon population transfer with near-resonant chirped pulses

“…When the detuning from the intermediate level is chosen sufficiently large compared to the width of the sodium hyperfine structure, the three-level approximation is in good agreement with the more complex treatment. The coherent interaction between a three-level system and two fields has been analyzed for certain processes [27][28][29][30][31][32][33][34]. For instance, in the particular case of each field being in resonance with the intermediate state, the pulse area of each pulse for complete transfer of the occupation probability from the ground state to the highest state is simply √ 2π, with the pulse area defined as ∞ −∞ Ω(t)dt, where Ω(t) = µE(t)/h is the Rabi frequency of the transition, µ is the electric dipole moment and E(t) is the electric field amplitude of the laser pulse.…”

Effect of interference between three-level inversions on the inversion process and amount of inversion in a four-level system

“…It will be interesting to find the changed ratio of Rabi frequencies due to the interference effect in the optimal detuning method (Choe et al 1995a), in which the four-level inversion is complete. In a case where V 1 (t) = V 2 (t), we can obtain the state |u f as…”

“…As another interesting case, we consider the inversion in the optimal detuning method using lasers which are not delayed (Choe et al 1995a). Let us put…”

“…In a three-level system, as well known methods of population inversion, we can use the adiabatic passage method (Oreg et al 1984, Carroll and Hioe 1990, Kuklinski et al 1989 using time-delayed pulses and the optimal detuning method (Choe et al 1995a) using optimal frequency detuning to completely overlap laser pulses. If we restrict our discussion to the case of two-photon resonance, it is known that the two-photon coherences in the adiabatic passage and the optimal detuning methods have in-phase and out-of-phase components, resulting in population inversions in the dispersive and the absorptive processes, respectively (Kim et al 1997).…”

Trichromatic π-Pulse for Ultrafast Total Inversion of a Four-Level Ladder System

“…The coherent interaction between a three-level system and two fields has been studied theoretically for different processes [14][15][16][17][18][19][20][21]. In a three-level ladder system with resonant fields the solution for π-pulse bichromatic control is analytical [17].…”