An unstable imaging resonator, comprising: a feedback mirror and a primary mirror which provide unstable resonator oscillation of a laser signal which propagates along an optical axis between the feedback mirror and the primary mirror; a plurality of laser disks and reflecting mirrors each exhibiting a principal surface on which said laser signal impinges, said principal surface having a normal in its center; a first plurality of said laser disks (230a-c) being disposed in a first vertical plane such that said normal of each of said first plurality of said laser disks (230a-c) is perpendicular to said first vertical plane, and a second plurality of said laser disks (230d-f) being disposed in a second vertical plane such that said normal of each of said second plurality of said laser disks (230d-f) is perpendicular to said second vertical plane, said second vertical plane being opposite to said first vertical plane, wherein the plurality of laser disks (230a-f) are disposed in a central horizontal plane, such that said normal of each of said laser disks is in said central horizontal plane; wherein each of the laser disks have an active thin disk gain medium; and a first plurality of said reflecting mirrors (240e-h) being disposed in the first vertical plane, such that said normal of each of said first plurality of reflecting mirrors (240e-h) is perpendicular to said first vertical plane, and a second plurality of reflecting mirrors (240a-d) disposed in the second vertical plane 206, such that said normal of each of said second plurality of reflecting mirrors (240a-d) is perpendicular to said second vertical plane, wherein a first set of the reflecting mirrors (240b, 240d, 240e,240g) is disposed in a lower horizontal plane and a second set of reflecting mirrors (240a, 240c, 240f, 240h) are disposed in an upper horizontal plane such that said normal of each of said second set of reflecting mirrors (240a, 240c, 240f, 240h) is in said upper horizontal plane; wherein said lasers disks and reflecting mirrors are located on said optical axis wherein respective laser disks and reflecting mirrors adjacent in the optical axis are positioned to provide a 1:1 imaging system therebetween. a feedback mirror and a primary mirror which provide unstable resonator oscillation of a laser signal which propagates along an optical axis between the feedback mirror and the primary mirror; a plurality of laser disks and reflecting mirrors each exhibiting a principal surface on which said laser signal impinges, said principal surface having a normal in its center; a first plurality of said laser disks (230a-c) being disposed in a first vertical plane such that said normal of each of said first plurality of said laser disks (230a-c) is perpendicular to said first vertical plane, and a second plurality of said laser disks (230d-f) being disposed in a second vertical plane such that said normal of each of said second plurality of said laser disks (230d-f) is perpendicular to said second vertical plane, said second vertical plane being opposite to said first vertical plane, wherein the plurality of laser disks (230a-f) are disposed in a central horizontal plane, such that said normal of each of said laser disks is in said central horizontal plane; wherein each of the laser disks have an active thin disk gain medium; and a first plurality of said reflecting mirrors (240e-h) being disposed in the first vertical plane, such that said normal of each of said first plurality of reflecting mirrors (240e-h) is perpendicular to said first vertical plane, and a second plurality of reflecting mirrors (240a-d) disposed in the second vertical plane 206, such that said normal of each of said second plurality of reflecting mirrors (240a-d) is perpendicular to said second vertical plane, wherein a first set of the reflecting mirrors (240b, 240d, 240e,240g) is disposed in a lower horizontal plane and a second set of reflecting mirrors (240a, 240c, 240f, 240h) are disposed in an upper horizontal plane such that said normal of each of said second set of reflecting mirrors (240a, 240c, 240f, 240h) is in said upper horizontal plane; wherein said lasers disks and reflecting mirrors are located on said optical axis wherein respective laser disks and reflecting mirrors adjacent in the optical axis are positioned to provide a 1:1 imaging system therebetween.