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The Journal of Chemical Physics

Laser pulse induced n-photon absorption in an atom or molecule aligned by a static electric field

Gerald F. Thomas

Published Jan 1, 1987• 9 citations
Publisher

Abstract

Within the rotating-wave and Magnus approximations, the electrical anharmonicity induced in an atom or molecule aligned by a static electric field is shown to lead to the absorption of many photons delivered by a Gaussian-modulated laser pulse of finite intensity and duration. In the presence of the static field the effective area of the near-resonant pulse vanishes at prescribed intensity-dependent frequencies, resulting in the appearance of satellite fringes flanking the usual Gaussian line shape. The transition probability for excitation of the oriented system by a train of phase-coherent Gaussian pulses is calculated.

DOI
10.1063/1.452594

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The consequences of having state-specific diagonal transition matrix elements on the interaction of a two-level system with a laser field and a static electric field are examined within the dipole and rotating-wave approximations. A finite difference between the permanent dipole moments can result in the appearance of subsaturating ancilliary fringes flanking the usual Lorentzian transition resonance. The requisite conditions for a two-level system to exhibit an oscillatory line shape are discussed. These fringes arise from the essential transparency of the system to the field at prescribed intensity-dependent frequencies.
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