Narrow coherence-induced peaks in Doppler-free spectra of thorium

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Journal of the Optical Society of America, Part B: Optical Physics; (United States)

DOI:https://doi.org/10.1364/JOSAB.11.000542· OSTI ID:7116673

Tissue, B M ^[1]; Fearey, B L ^[2]

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1. Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)
2. Los Alamos National Laboratory, NIS-7, MS E541, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)

We report the observation of narrow peaks in Doppler-free spectra of thorium. The peaks are superimposed upon saturation-broadened line profiles in thorium atomic spectra by use of counterpropagating cw laser beams with resonance ionization mass spectrometry detection. At low laser powers the spectra show a conventional Lamb dip. As the laser power is increased, a narrow peak obscures the dip (for two of four transitions studied). The narrow peak is attributed to coherence effects at high laser powers. To confirm this assignment, we calculated the saturated absorption line shapes by using the theory of Haroche and Hartmann [Phys. Rev. A [bold 6], 1280 (1972)]. The spectral simulations reproduce the narrow peaks and show the same dependence with laser power and transition strength as do the data. There are some quantitative discrepancies, particularly in the overall saturation broadening, but given that there were no adjustable parameters in the calculations, the agreement between theory and experiment is considered quite good. The Einstein [ital A] coefficients used in the calculations were determined from an analysis of the laser-power dependence of the saturation broadening for each transition.

• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7116673
• Journal Information: Journal of the Optical Society of America, Part B: Optical Physics; (United States), Journal Name: Journal of the Optical Society of America, Part B: Optical Physics; (United States) Vol. 11:4; ISSN JOBPDE; ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION SPECTRA
ACTINIDES
EINSTEIN COEFFICIENTS
ELEMENTS
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
LAMB SHIFT
LINE NARROWING
LINE WIDTHS
METALS
MILLIWATT POWER RANGE
OPTICAL PUMPING
POWER RANGE
PUMPING
SPECTRA
SPECTRAL SHIFT
THORIUM
ULTRAVIOLET SPECTRA