Excited-state absorption and energy output of laser ruby

The laser performance, luminescence intensity and absorption in excited state of rubies annealed in reducing or oxidizing atmosphere is given. Rubies doped with Mg, Ti or Fe were compared to those containing Cr only. The decrease of energy output is caused by the non-radiative transitions from the excited states to the ground⁴A₂ state. O^– centre developed by the presence of the large ions facilitate the transitions from the upper excited states only, whereas Fe and to a less extent Ti ions make the non-radiative transition from the metastable²E level to the⁴A₂ level possible. Ti³⁺ ions filter also the UV content of the flashlight and prevent the transition from the²E to the higher states.