Static profile calorimetry of laser materials

In conventional laser calorimetry, the surface and bulk absorption coefficients are normally derived from experiments on a series of samples of graduated length. The measurement of transients in the heating of long bar samples has also been used for this purpose. This paper describes a third analytic technique for calorimetry on bar samples, namely, the direct observation of the temperature profile established after the initial transients have subsided. With care, this technique should provide accurate measures of both bulk and surface absorptions. In particular, it will show variations of bulk coefficient along the bar as well as the asymmetric surface losses that are expected as a result of Fresnel reflections.