Atomic spectra constants

The recent development of continuous, reliable lasers has made it possible to provide new spectroscopic data. New techniques based on the specific properties of lasers (monochromaticity, energy density...) have been introduced into the field of optical spectroscopy, enabling more precise measurements of the spectral wavelengths of atomic transitions, transition dipole moments, hyperfine constants...

However, despite the obvious advantages and success of tunable lasers in fundamental atomic and molecular spectroscopy, lasers have not yet replaced conventional tools in analytical spectroscopy. Methods using these laser techniques in chemical analysis are only applied in a handful of research laboratories worldwide. This is certainly due to the fact that the most widely used tunable laser, the dye laser, is still too complicated and expensive to be an alternative to conventional methods in routine analysis. The limited wavelength range of dyes results in limited multi-elemental analysis capability, unless the laser dye can be changed automatically. Dye degradation during operation leads to a decrease in laser power over time. Finally, lasers are sensitive instruments that often require realignment and cleaning of the optics. In this respect, the rapid development of semiconductor lasers (diode lasers) opens up a wide range of applications in the field of analysis, as these lasers do not have the disadvantages mentioned above.

There is already a strong demand from industry, medicine and research for analytical techniques enabling the determination of absolute quantities of trace elements in the femtogram (10 ^–15 g) or attogram (10 ^–18 g) range.