Effect of the odd-photon destructive interference on laser-induced transparency and multiphoton excitation and ionization in rubidium

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.54.4218· OSTI ID:392015

Deng, L; Garrett, W R; Payne, M G ^[1]; Lee, D Z ^[2]

---

1. Chemical Physics Section, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
2. Physics Department, University of British Columbia, Vancouver (Canada)

We report experimental results on two-color multiphoton ionization and four-wave-mixing production under conditions where one form of laser-induced transparency (LIT) occurs. Under the conditions of LIT, multiphoton-ionization line shapes obtained by tuning one laser through a two-photon resonance exhibit a pronounced Autler-Townes splitting at low concentrations, when a second laser couples the two-photon state to a third level. In this concentration region we observed a four-wave-mixing field that increased quadratically with concentration. As the concentration is increased the Autler-Townes splitting starts to decrease, and disappears completely as a critical concentration is reached. Simultaneously, the four-wave-mixing field intensity starts to level off and finally becomes concentration independent. These observations are explained in terms of odd-photon destructive interference between different excitation pathways. In rubidium, we demonstrate that above concentrations of {ital n}{approx_equal}5{times}10{sup 14} cm{sup {minus}3} the four-wave-mixing field is concentration independent and the multiphoton-ionization line shape shows no Autler-Townes splitting, and the width of the line shape is determined by the laser bandwidth. The results presented here demonstrate that destructive interference significantly limits the high-efficiency and high-intensity nonlinear optical generation promised in early studies on LIT, at least for the multimode laser system used in the present experiment. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Oak Ridge National Laboratory
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 392015
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 5 Vol. 54; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
EXCITATION
FOUR-WAVE MIXING
INTERFERENCE
IONIZATION
LASER RADIATION
LINE SHAPE
MULTI-PHOTON PROCESSES
PHOTON-ATOM COLLISIONS
RUBIDIUM