Employing collector optics that has a sacrificial reflective surface can
significantly prolong the useful life of the collector optics and the
overall performance of the condenser in which the collector optics are
incorporated. The collector optics is normally subject to erosion by
debris from laser plasma source of radiation. The presence of an upper
sacrificial reflective surface over the underlying reflective surface
effectively increases the life of the optics while relaxing the
constraints on the radiation source. Spatial and temporally varying
reflectivity that results from the use of the sacrificial reflective
surface can be accommodated by proper condenser design.