that of a dc excited waveguide laser of similar length fig3 shows a cross section of a waveguide slot type laser which has been fabricated according to the present invention the ceramic block 21 has the slot 22 ground along the center of the upper surface thereof the flat cover or top 17 is of the same ceramic material as block 21 and is bonded thereto by means of a bead of bonding material 19 around the edges of the joint between these two ceramic pieces one of the advantages of hard ceramic materials like alumina and beryllium oxide is that they are much easier to bond to themselves and to metals than is boron nitride and other soft ceramics the laser of fig3 has applied thereto a pair of parallel metal plates or electrodes one mounted above ceramic cover 17 and designated by reference numeral 15 and the second 23 attached to the lower surface of ceramic block 21 these electrodes are connected to an rf radio frequency signal source 25 which provides rf excitation for the gaseous laser medium within the waveguide cavity 22 fig4 illustrates a waveguide type laser in which two parallel slots are ground into a common ceramic block 31 to form twin co 2 lasers also in this embodiment the top ceramic cover is dispensed with and the metal electrode 27 is placed directly on top of the ceramic block to perform the dual functions of the upper.