THREE-APERTURE INTERFEROMETRIC PROJECTION DEVICE FOR PRODUCING A SPOT COMPRISING FINE STRUCTURES

摘要

The present invention relates to a device for projecting a beam of coherent light onto a target (1), which includes a projection system (4) for projecting light onto the target (1). The projection system (4) comprises means (5) for splitting the beam (3) into sub-beams (6, 6', 6'') the projection means 7, 7', 7'' and the associated focusing and pointing means 9, 9', 9'' thereof. The device is capable of jointly providing the coherent projection of said three sub-beams (6, 6', 6'') onto one and the same area (1') of said target (1). As far as possible, the three sub-beams (6, 6', 6'') have the same intensity, the same polarization, the same optical path length and the same pupil orientation at the respective apertures 7, 7', 7''. The present invention also relates to the use of the device for measuring the slope of a wavefront incident on a target.