Analysis of thermal effects in an orthotropic laser medium

The temperature, thermal stress, thermal strain, and optical path difference (OPD) in an orthotropic laser medium under Gaussian, top-hat, and uniform pumping schemes are solved both analytically and numerically. The results indicate that, provided the same total heat loading, the thermal effects under the top-hat pumping scheme are lower than under the Gaussian pumping scheme, whereas the thermal effects under uniform pumping are the least significant of all; in the absence of external forces, the orthotropic thermal properties have more significant effects on the thermal strain than on the thermal stress. The theoretical OPD agrees well with published experimental data and shows evident orthotropy.