METHOD AND DEVICE FOR TESTING OPTICAL IMAGING SYSTEMS

Optical imaging systems are used for making microstructures, and have to be very precise. In order to test these imaging systems, a new method, and a device for carrying out this method, are described in which two interferograms are made and compared. In a first step, an interferogram of an original pattern is made, followed by a second step in which an interferogram of a copy of the original pattern is produced using the identical conditions used to form the first interferogram. The pattern copy is made in the imaging system to be tested. In a third step, the two interferograms are compared with one another to provide a measure of the accuracy of the imaging system. This technique can be used for testing imaging systems which produce only a mirror image.