Abstract

A technique of dual-laser ionization (DLI) is employed to detect Na trace released in an acetylene/air flame. In comparison with laser-enhanced ionization (LEI), a measurement of ion enhancement by the DLI method is found to be as large as two orders of magnitude. The ratio of DLI/LEI depends upon various factors, such as the second-step transition probability, the laser intensity, the transition linewidth, and the collisional ionization rate involved in the LEI mechanism. However, the relative ion enhancement with respect to the various second-step excitations is largely dominated by the ratio of the corresponding second-step transition probability. On the basis of this factor, a comparison between observation and estimation is found to be in satisfactory agreement.

Laser-enhanced flame ionization detector

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

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)

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 ionization detection of trace copper in high salt matrices

George J. Havrilla and Christopher C. Carter
Appl. Opt. 26(17) 3510-3515 (1987)

Experimental demonstration of a Raman scattering detector based on laser-enhanced ionization

B. W. Smith, P. B. Farnsworth, J. D. Winefordner, and N. Omenetto
Opt. Lett. 15(14) 823-825 (1990)