Abstract: A solid-state lasers and method of operating the laser is described having a microwave-driven (MWD) visible excimer fluorescence source for exciting a solid-state laser. The laser of this invention provides an efficient, compact, and tunable solid-state laser preferably for use with tunable vibronic laser crystals. Further described is an excimer lamp that has the capability of provided illumination at varying wavelengths. In one embodiment an excimer is selected in a desire to maximize light absorption in plants. This is accomplished by tuning the lamp to provide an output compatible with plant chlorophyll.