Abstract: A high resolution, deep UV beam delivery system for exposing a surface, directly or through a mask, for the purpose of photolithography, surface cleaning, microstructuring, pattern microimaging, surface modification or the like includes a deep UV radiation source for generating a beam of deep ultraviolet radiation along a first path; single element variable attenuator apparatus disposed in the first path for adjustment of the deep UV beam energy in the first path; an optical system in the first path for homogenizing and shaping the deep UV beam energy in the first path; a second radiation source for generating visible wavelength radiation along a second beam path; merging structure for merging radiation energy in the first path and radiation energy in the second path for passage along a common third path; beam splitter structure in the third path for directing radiation energy in the third optical path along a fourth optical path angularly offset from the third path; large area mirror structure having a numer