Nuclear Radiation Damage to Ruby Lasers

The power output of ruby lasers is decreased when they are exposed to high energy ionizing radiation. The causes for this degradation are: (1) the absorption of the laser light by a radiation-induced absorption at the lasing wavelength, (2) a change in the valence state of the lasing impurity, Cr3+ ions and (3) the absorption of the flash lamp pump light by radiation induced absorption. By experimentally determining the magnitude of each of these damage parameters, one is able to estimate for a particular absorbed dose the expected laser degradation. The technique for performing this calculation as well as the experimental verification of the prediction are reported.