Abstract: A waveguide carbon dioxide (CO.sub.2) laser includes a six-sided laser block comprising first and second triangular end sections and a rectangular insert block. The two triangular end sections include a waveguide grid comprising two sets of parallel waveguide channels intersecting at right angles and optically coupled by strip mirrors disposed along the edges of the triangular sections. The rectangular insert block also includes a set of parallel waveguide channels which are congruent with and aligned parallel to the waveguide channels of the two triangular end sections, thereby extending the cavity length of a multiply folded waveguide laser without a corresponding increase in the number of optical folds, the number of folding mirrors, or the value of distributed loss.

Abstract: This new technique for stacking multiply folded optical paths in an extended region of a laser resonator within a gaseous medium. The path segments are connected together by a set of mirrors located along the resonator perimeter. Moreover, this invention involves a system of stacking unit tiles, each minim containing a multiply folded path, into larger domains. A multiplicity of mirrors is located in the laser resonator around the perimeter of stacked minims. A longer optical path is achieved without a corresponding increase in the number of folding elements, by stacking the minims together and thereby extending the length of the folding elements. The resulting domains fully cover the plane with a grid of evenly spaced and intersecting optical paths. The laser resonator can be used in either a laser oscillator or amplifier, and in either pulsed or continuous wave mode.

Abstract: The laser resonator of the present invention has multiply folded optical paths in an extended region by utilizing a set of front surface reflecting elements. The resonator can be used in a gas laser oscillator or amplifier, in either continuous wave mode or pulsed mode. This optical path is folded into larger domains within a polygonal area of the laser cavity, thereby achieving increasingly longer laser paths without a corresponding increase in the number of folding elements. The resulting domains fully cover the plane with a grid of evenly spaced and intersecting optical paths. In one embodiment, the invention consists of a waveguide gas laser system with a ceramic block having a multiply folded optical path of intersecting waveguide channels cut into the block. The reflecting mirrors of the laser resonator are integrally attached to the ceramic block, enhancing the durability of the laser resonator and reducing the size.