Theory of the cancellation of four-photon resonances by an off-resonance three-photon cancellation

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.46.465· OSTI ID:7038568

Elk, M; Lambropoulos, P; Tang, X ^[1]

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1. Department of Physics, University of Southern California, Los Angeles, California 90089-0484 (United States)

We present a complete account of our recent work (Phys. Rev. A 44, 31 (1991)) in which we investigate the theory of cancellation by interference between the absorption of three fundamental laser photons and one third-harmonic photon. The theory is formulated in terms of the density matrix so as to take detunings, dephasing, and laser bandwidth into account. The result is a theory of cancellation for finite detuning that explains how four-photon resonances can be canceled by a three-photon mechanism if there is an atomic level at near-three-photon resonance. The treatment is extended to focused beams and the interplay between phase matching and cancellation is investigated. We obtain explicit conditions for cancellation to occur, and perform calculations pertaining to a recent experiment where cancellation of 4+1 resonantly enhanced multiphoton ionization has been observed.

• DOE Contract Number: FG03-87ER60504
• OSTI ID: 7038568
• Journal Information: Physical Review A. General Physics; (United States), Journal Name: Physical Review A. General Physics; (United States) Vol. 46:1; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
CANCELLATION
DENSITY MATRIX
IONIZATION
MATRICES
MULTI-PHOTON PROCESSES
NONLINEAR OPTICS
OPTICS
PRESSURE EFFECTS
RESONANCE