An imaging apparatus for exposing a pattern onto a substrate has an illumination source that is energizable to generate a polarized exposure illumination beam of an actinic wavelength range and a mask disposed to impart the pattern to the polarized exposure illumination beam. A polarization beam splitter defines an illumination path that conveys the generated polarized exposure illumination beam through a quarter wave plate and plano-convex lens and toward a concave mirror and further conveys a reflected exposure illumination beam from the concave mirror toward an exposure plane for exposing the imparted pattern onto the substrate. The exposure plane is defined by the concave mirror, the plano convex lens, and the polarization beam splitter.