Abstract: A housing for a slab laser gain media with a rectangular cross section which provides for a uniform flow of coolant over the slab top and bottom surfaces (18) and (20), while insulating the slab side surfaces (14) and (16). The slab gain media is bonded between two tabs at each end of the housing (48a, 48b, 50a, 50b). The slab top and bottom surfaces are made level with the tab top and bottom surfaces. Seals are placed on the continuous surface formed by the slab top and bottom surfaces and the tab top and bottom surfaces, thus sealing the ends of the housing, and also surrounding the coolant inlets and outlets. Windows (32) and (34) are then placed on top of each seal to form two thin cavities confining the coolant to flow across the slab top and bottom surfaces (18) and (20), and allowing for the close-coupling of either one or two pump sources, such as a two dimensional laser diode array assembly (58) and (60).