OPTICAL DESIGN FOR PAGE ACCESS TO VOLUME OPTICAL MEDIA

4F lens designs are optimized for parallel access to volume holographi c memories. Aberrations, diffraction, and component tolerancing are co nsidered for their impact on parallelism, crystal information density, and overall system storage density. We find that a parallelism of gre ater than or equal to 10(5) bits per page and a crystal information de nsity of approximate to 2 Mbits/mm(3) are achievable with standard opt ical elements and that advanced designs offer significant improvements . Crystal surface tolerance measurements show that a diffraction-limit ed performance is achievable over apertures of 7.1 mm for LiNbO3 and 1 .5 mm for KNSBN(60). Lens-tolerancing simulations show that lens decen ter degrades peak parallelism and peak crystal information density. An ew nonconfocal 4F system design with improved performance is presented . (C) 1996 Optical Society of America