Thermal conductivity of synthetic garnet laser crystals

Laboratory of Laser Technology and Application Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 1125, Hefei 230031, P.R. China

Corresponding author: hjiang@aiofm.ac.cn

Received: 2 November 2006
Revised: 29 April 2007
Accepted: 9 May 2007
Published online: 13 June 2007

Abstract

The thermal conductivities of nine different synthetic garnet laser crystals at various temperatures, range from 273 to 393 K have been investigated by instantaneous measurement method. The results show that the thermal conductivity of each crystal decreases exponentially with the temperature increasing. It is notable that, different host crystals, such as YAG, GGG, and GSGG have different thermal conductivity, which is attributed to the crucial influence of crystal structure and composition on the absolute value of their thermal conductivity. Moreover, with respect to the same host crystals, the impurity scattering also results in the change of their thermal conductivities. This is because that a higher concentration of doped ions leads to a more phonon scattering modes, which results in a shorter mean free path of the phonons and a lower thermal conductivity. In addition, different host crystals have various dependences of thermal conductivity on dopant concentration. This works provides reliable and useful information for designing high power, high quality, and high stability laser devices.