Simulating heat generation in the monoblock laser using finite element analysis

Abstract

Under photonic pumping Nd:YAG (Neodymium Yttrium Aluminum Garnet) generates a significant amount of heat as a result of quantum deficit and non-radiative absorption sites, this excess heat results in thermal deformation and a shift in the index of refraction of Nd:YAG causing a net change in Optical Path Length (OPL). Finite Element Analysis (FEA) techniques provide a powerful approach for digital design and analysis of complex thermo-mechanical systems; unfortunately, finite element software packages do not use light as a traditional loading mechanism nor track optical properties. This research has sought to establish a methodology to interface thermal loading as a result of photonic conversion with traditional FEA practices and track the resulting optical effects. The ABAQUS software package interfaced with a python driven input procedure has been used to develop a representation of photonic loading in the FEA environment. This modeling method has been calibrated utilizing interferometry imaging of a pulsed Nd:YAG system tracking the resultant OPL and comparing these results to FEA predictions. FEA predictions were developed that matched experimental measurements within 0.5 waves at the 1064nm laser line for Nd:YAG.