Calculated thermal distribution of non-uniform side-pumped laser rod by BEM and detection and simulation of phase shift in emerging ray

In this study, a steady-state heat transfer equation in a side-pumped Nd:YAG laser crystal is solved numerically using the Boundary Element Method (BEM). The temperature distribution and its gradient are calculated at arbitrary points inside the rod. Subsequently, by solving the ray equation and calculating the optical path integral along the length of the rod, the phase shift of the passing rays is obtained. Furthermore, this thermal phase shift is detected in practice by an interferometric experiment. Excellent agreement is observed between the calculated and experimental results.

► Fluorescence measurement of a pumped laser crystal. ► Obtaining the pump distribution function. ► Solving the thermal equation, considering completely non-uniform pump distribution. ► Doing an interferometric experiment to observe the effect of Thermal Phase Shift. ► Simulation of Thermal Phase Shift by BEM.