Estimation of thermal fracture limits in quasi-continuous-wave end-pumped lasers through a time-dependent analytical model.

ABSTRACT

A time-dependent analytical thermal model of the temperature and the corresponding induced thermal stresses on the pump face of quasi- continuous wave (qcw) end-pumped laser rods is derived. We apply the model to qcw diode-end-pumped rods and show the maximum peak pump power that can be utilized without fracturing the rod. To illustrate an application of the model, it is applied to a qcw pumped TmYLF rod and found to be in very good agreement with published experimental results. The results indicate new criteria to avoid fracture when operating TmYLF rods at low qcw pump duty cycles.