Abstract: A folded slab waveguide laser having a hybrid waveguide-unstable resonator cavity. Multiple slab waveguides of thickness ‘t’ supporting vertical waveguide modes are physically arranged above one another in a stack and optically arranged in series through one or more cavity folding assemblies with curved mirrors. A gain medium such as a gas is arranged in each slab. Each cavity folding assembly is designed to redirect the radiation beam emitted from one slab waveguide into the next waveguide and also at the same time to provide a focus for the radiation beam so that a selected vertical waveguide mode (or modes) is (or are) coupled efficiently into the next slab.

Abstract: A radio frequency, RF, slab laser comprising a live electrode (102) and a ground electrode (108) whose inwardly facing surfaces face each other to form a gap for forming a plasma discharge when the live electrode is supplied with a suitable RF drive signal. The electrodes are enclosed in a vacuum space by a vacuum housing (114) with an access aperture (116). The access aperture is sealed with a vacuum flange (70) that comprises an electrically insulating connector. A plurality of hollow conductors (62) are arranged to extend through the vacuum flange into the vacuum space and connect with the live electrode. The hollow conductors connect to the live electrode to supply it with its RF drive signal and also coolant fluid which is distributed through fluid circulation channels (80a, 80b). Coolant fluid is supplied to the live electrode through certain ones of the hollow conductors and taken out by others.

Abstract: A folded slab waveguide laser having a hybrid waveguide-unstable resonator cavity. Multiple slab waveguides of thickness ‘t’ supporting vertical waveguide modes are physically arranged above one another in a stack and optically arranged in series through one or more cavity folding assemblies with curved mirrors. A gain medium such as a gas is arranged in each slab. Each cavity folding assembly is designed to redirect the radiation beam emitted from one slab waveguide into the next waveguide and also at the same time to provide a focus for the radiation beam so that a selected vertical waveguide mode (or modes) is (or are) coupled efficiently into the next slab.

Abstract: A folded slab waveguide laser having a hybrid waveguide-unstable resonator cavity. Multiple slab waveguides of thickness ‘t’ supporting vertical waveguide modes are physically arranged above one another in a stack and optically arranged in series through one or more cavity folding assemblies with curved mirrors. A gain medium such as a gas is arranged in each slab. Each cavity folding assembly is designed to redirect the radiation beam emitted from one slab waveguide into the next waveguide and also at the same time to provide a focus for the radiation beam so that a selected vertical waveguide mode (or modes) is (or are) coupled efficiently into the next slab.

Abstract: A folded slab waveguide laser having a hybrid waveguide-unstable resonator cavity. Multiple slab waveguides of thickness ‘t’ supporting vertical waveguide modes are physically arranged above one another in a stack and optically arranged in series through one or more cavity folding assemblies with curved mirrors. A gain medium such as a gas is arranged in each slab. Each cavity folding assembly is designed to redirect the radiation beam emitted from one slab waveguide into the next waveguide and also at the same time to provide a focus for the radiation beam so that a selected vertical waveguide mode (or modes) is (or are) coupled efficiently into the next slab.