Diffraction images of clear slits by optical systems with annular apertures apodised by hamming filters

The advent of the laser in the early sixties has imparted a fillip to the s tudies on coherent imagery of extended objects in Fourier optics. The coher ent illumination produces unwanted edge ringing in the images. Apodisation mitigates edge ringing. Literature is sufficiently rich in these studies wi th circular apertures, but it is not so adequate for annular apertures. The results of our studies on coherent diffraction images of clear slits by ap odising optical systems with annular apertures using Hamming amplitude filt ers are presented. Circular apertures have been studied as a special case o f annular apertures.