An apparatus and method is disclosed which may comprise an EUV drive laser system comprising: a solid state seed laser master oscillator laser; a gas discharge excimer laser gain generator producing a drive laser output light beam. The solid state seed laser may comprise a third harmonic Nd: YLF laser, which may be tunable. The gas discharge excimer gain generator laser may comprise a XeF excimer laser power amplifier or power oscillator. The solid state laser may comprise a tunable laser tuned by changing the temperature of a laser crystal comprising the solid state laser, or by utilizing a wavelength selection element, e.g., a Lyot filter or an etalon.
