High resolution laser spectroscopy .

With his experiments, Apostolos Pantinakis was the first to verify the predictions of the theory of hyperfine predissociation, by measuring differences in intensities and in lifetimes between different hyperfine sublevels, http://opensigle.inist.fr/handle/10068/687924 . He conducted the experiments before the theory was established! He used some of the techniques in high resolution laser spectroscopy, pioneered by the Nobel prize winners: http://nobelprize.org/nobel_prizes/physics/laureates/2005/hansch-lecture.html , http://nobelprize.org/nobel_prizes/physics/laureates/2005/hall-lecture.html To interpret them, he used an approximation proposed by Levenson and Schawlow : http://nobelprize.org/nobel_prizes/physics/laureates/1981/schawlow-autobio.html . Hyperfine predissociation influences adversely the spectral width of the frequency stabilized laser , hence the wavelength-based definition of the unit of length and high resolution spectroscopy in general