An illumination system of a microlithographic projection exposure apparatus comprises an optical integrator (70), which includes a first optical raster plate (74) and a second optical raster plate (76).

An illumination system of a microlithographic projection exposure apparatus (10) comprises an optical integrator (52; 152) that includes an array (54c; 154b) of optical raster elements (56; 156).

A condenser (72) superimposes the light beams associated with the optical raster elements in a common field plane (71).

A second optical raster (30; 130; 230) element is positioned in or in close proximity to the pupil plane (28).

The system further comprises an optical raster element (34; 434) including a plurality of microlenses and/or diffractive structures.

There are as many as 200 manual processes involved in making an optical frame.

There are as many as 200 manual process involved in making an optical frame.

The third optical raster element (36; 136; 236), which can be a diffractive optical element, introduces an additional degree of design freedom for the modification of the angular distribution of the projection light bundle.

The optical raster element (72) has a plurality of light entrance facets (92) each being associated with one of the secondary light sources (95).

The invention described comprises an optical screen with which the required copies can be produced by using the photomechanical process of printing form production.

The first optical raster element extends in a first pupil plane (28) of the illumination system (10) and is designed such that the geometrical optical flux of the system is increased perpendicular to a scan direction of the projection exposure apparatus.

An illumination system of a microlithographic projection exposure apparatus comprises an optical raster plate (54a) having a light entrance surface (55).

An exchange unit (94) is configured to hold the optical raster element (100a, 100b, 100c) in the second mode of operation such that it is inserted into the light path.

A third optical raster (36; 136; 236) element is positioned in or in close proximity to a second plane (34) that is also con jugated to the pupil plane (28) by Fourier transformation.