IMPROVEMENTS IN THE CAPACITY OF COMPUTER-GENERATED HOLOGRAPHIC STORAGE USING THE LEE METHOD WITH SPARSE MULTIVALUED RECONSTRUCTIONS

The use of sparse multivalued data encodings for the purpose of increa sing the capacity of parallel-access optical memories based on Fourier -transform computer-generated holography is discussed. Results based o n the Lee method indicate that a sparse encoding of nonbinary data wor ds can be used to increase the storage-area utilization efficiency fro m 35% to >70%. It is also found that for signal-to-noise ratios greate r than 200, five-level data encoding can be used to achieve bit error rates less than 10(-12) reliably with 60% area efficiency.