Thermal Stresses and End-Bulging in Cylindrical Laser Rods Under Longitudinal Diode Laser Pumping

Abstract

Three-dimensional thermo-mechanical finite element analysis of conventional and composite cylindrical laser rods under the conditions of longitudinal pumping of the continuous wave diode laser is presented. First, the heat conduction problem with prescribed cooling boundary conditions is solved. Then, the 3D stress and bulging of entrance and exit faces are analyzed. It is shown that the frequently used plane strain and plane stress approximations significantly overestimate the values of face bulging of conventional and particularly composite laser rods under the conditions of homogeneous and inhomogeneous heating.

Keywords:

• Conventional and composite laser rods
• End-bulging
• Finite element method
• Thermal stresses and displacements