High energy laser mirror

A high energy laser mirror-heat exchanger is described which comprises a faceplate supporting a mirrored surface, a manifold plate adjacent the faceplate and defining a plurality of passageways for distributing fluid coolant to the adjacent faceplate surface, a heat exchanger adjacent the manifold plate having a plurality of wall members configured in a isogrid configuration which may define a plurality of triangularly shaped passageways therebetween for conducting coolant to the manifold plate the intersections of said wall members defining a plurality of insulated passageways for conducting coolant away from said manifold plate, and a backing plate attached to the heat exchanger including coolant inlet and outlet means.