Radiationless processes and their implications for new laser materials

It is noted that the single-configurational coordinate (SCC) diagram pictures electronic states as curves in energy-coordinate space. A review is given of the work reported by Struck and Fonger in 1974, 1975, 1976, 1978, and 1979 on the quantum-mechanical implications of SCC-diagrams for parabolic energy curves and on extensions of these implications to multiple coordinates and energy transfers. It is pointed out that the theory is of fundamental importance in understanding tunable condensed-phase lasers, for example, dye lasers, color-center lasers, and lasers involving the electronic states of 3dn or 4fn configurational ions. What is more, the theory of the nuclear factor of optical and nonradiative transitions developed by Struck and Fonger has been shown experimentally to be effective in understanding the relative radiative and nonradiative transition rates in luminescent solids.