Design of convex-shaped transparent heat spreaders for symmetrical cooling of a thin-disk laser crystal by mechanical pressing

Abstract

We present the design for a double-sided cooling of a thin-disk laser crystal using transparent, convex-shaped heat spreaders. The thermal contact between laser crystal and heat spreaders is established without bonding by solely applying an axial compressive force. A model of the contact behavior taking into account the deformation of the surfaces of the heat spreaders due to bending under mechanical loading is presented. The scope and accuracy of the modeling is verified by numerical simulations using the finite-element method. Based on the modeling, an exemplary design of the heat spreader which has been used for the first experimental demonstration of this concept is carried out. Based on the model, an almost ideal scalability of the heat transfer coefficient is predicted.