Abstract

Computer-generated holograms drawn by a laser scanner have several advantages for optical spatial filtering, as they can be drawn to the proper size directly without photographic reduction and provide the pixels of the hologram with gray scale.¹ We have designed and constructed such a system with some modifications to meet the requirements of using simple inexpensive optics and available electronics. A field lens is adapted to keep the scanning beams almost fixed as they enter the camera lens. This enables us to use a camera lens of f/1:2. The reduction ratio of the dimensions of the input aperture to the final pixel is chosen to be 1:32 so that the galvanometer-driven scanning mirror with a limited size of 12×9 mm² can still cover the first sidelobes of the diffraction pattern of the input aperture.

© 1981 Optical Society of America