Theory of the Pulsation of Fluorescent Light From Ruby

T. Muramoto, Yukio Fukuda, T. Hashi

E. W. Fisher, Zindel H. Heller

F. Barocchi, M. Mancini, Riccardo Pratesi +1 more

William Cutler, John Donaghue, Haridas Kumarakura +1 more

The unique optical properties of the ruby crystal that make it effective as a lasing medium were measured using a simple optical setup.Ruby's absorption of visible light was shown to be strongest at 420 and 550 nm, corresponding to its physical appearance as transparent pink.While the ruby crystal was illuminated with a 532 nm green laser, the R-line fluorescence peaked at 693.5 ± 1.1 nm.Finally, the fluorescence lifetime of ruby was measured by pulsing the laser with a signal generator and capturing the decaying fluorescence on a digital oscilloscope using a photodiode.An exponential decay time-constant of 3.6 ± 0.1 ms was obtained, corresponding to the fluorescence lifetime.

M. D. Galanin, V. N. Smorchkov, Zoya A Chizhikova

Milton Birnbaum

Fluorescence studies of the R-line emission of ruby laser rods over the temperature range of 77 to 300 K have disclosed several new features. In particular, for most of the ruby rods, the fluorescent decay time, τ, was not strictly exponential. Effects of this kind have been observed in the fluorescent decay of the 4F3/2 level of Nd3+ in YAG (yttrium aluminum garnet) and in Nd-doped glasses. In both cases, the nonexponential decay was interpreted as evidence for inhomogeneous line broadening effects, among which are strains, ion clustering, and other defects that modify the crystal field at the ion site. Our observations of nonexponential fluorescent decay in ruby are indicative of inhomogeneous line broadening effects in lightly doped (0/05%) ruby. In fact, inhomogeneous line broadening was observed in ruby at liquid helium temperatures, in the spectroscopic studies of A. L. Schawlow.