Abstract

Resonant two-photon ionization competes with laser-enhanced collisional ionization (LEI) in flames to ionize analyte atoms. The predominance of either mechanism for a given element depends on the excitation scheme as well as the level of irradiance. Optical saturation of the resonant transition through which the two-photon mechanism proceeds precludes observation of a second-order dependence of ionization signal on laser power. The laser power dependency of resonant two-photon ionization for a series of elements is examined, and results of diagnostic value regarding the probable ionization mechanisms are obtained.

Detection of trace amounts of Cr by two laser-based spectroscopic techniques: laser-enhanced ionization in flames and laser-induced fluorescence in graphite furnace

Ove Axner and Halina Rubinsztein-Dunlop
Appl. Opt. 32(6) 867-884 (1993)

Use of two-photon excitation in resonance ionization mass spectrometry

E. C. Apel, J. E. Anderson, R. C. Estler, N. S. Nogar, and C. M. Miller
Appl. Opt. 26(6) 1045-1050 (1987)

Photochemical effects in 243-nm two-photon excitation of atomic hydrogen in flames

J. E. M. Goldsmith
Appl. Opt. 28(6) 1206-1213 (1989)

Detection of traces in semiconductor materials by two-color laser-enhanced ionization spectroscopy in flames

Ove Axner, Mats Lejon, Ingemar Magnusson, Halina Rubinsztein-Dunlop, and Sten Sjöström
Appl. Opt. 26(17) 3521-3525 (1987)

Laser-enhanced flame ionization detector

Terrill A. Cool and John E. M. Goldsmith
Appl. Opt. 26(17) 3542-3551 (1987)