According to one exemplary embodiment, a projection objective is provided
and includes at least two non-planar (curved) mirrors, wherein an axial
distance between a next to last non-planar mirror and a last non-planar
mirror, as defined along a light path, is greater than an axial distance
between the last non-planar mirror and a first refracting surface of
lenses following in the light path. In one exemplary embodiment, the
first refracting surface is associated with a single pass type lens. The
present objectives form images with numerical apertures of at least about
0.80 or higher, e.g., 0.95. Preferably, the objective does not include
folding mirrors and there is no intermediate image between the two
mirrors, as well as the pupil of the objective being free of obscuration.