Absorption of pumping radiation by the yttrium aluminum garnet matrix of a neodymium-doped active element

A description is given of a method for the determination of the proportion of the heat evolved in a neodymium-doped active element due to the absorption of pumping radiation in the yttrium aluminum garnet (YAG) matrix. This method is based on a comparison of the evolution of heat from the active rod as a result of pumping with continuously operating krypton and xenon lamps producing the same stimulated output power. There is no need to measure the absorption spectrum of the active rod. Measurements carried out on four active elements revealed different absorptions and showed that crystals with stronger absorption in the matrix experienced a greater influence of the ultraviolet part of the pumping spectrum. The proposed method could be used to determine the quality of neodymium-doped YAG active elements.