Ē-Level Population of Ruby vs Pumping

Abstract
The Ē-level population of a cylindrical ruby rod is experimentally measured as a function of the pump energy at two points of the cross section of the rod, namely, the center and the periphery. The measurement is performed by measuring the fluorescent energy emitted after pumping by the points considered. The rod is pumped by a spiral flashtube. It is found that the experimental data of population vs pumping follow exponential curves as expected theoretically. From these curves the pump energy necessary for equalizing the populations between ground state and laser level is obtained in a straightforward way. The knowledge of this quantity leads to the measure of the losses (scattering plus diffraction) per pass in the rod. A value of ∼45% of losses is obtained for our rod.