Computer-generated holography for optical memory using sparse data words: capacity and error tolerance

Abstract

We discuss the capacity of parallel-access optical memories based on Fourier-transform computergenerated holography. Emphasis is placed on the fundamental capacity cost associated with Fouriertransform computer-generated holography encoding. Capacity cost is discussed in terms of encoder complexity, memory overhead, and media defect tolerance. Results indicate that a sparse encoding of binary data words that supports minimal hologram area usage is an effective scheme for memories based on Fourier-transform computer-generated holography. These results are independent of computergenerated- holography algorithm and media type.

<title>Storage capacity of pixelated paraxial diffractive elements</title>

“…The reason is that there exist a variety of efilcient computer-aided design methods which can be used with high flexibility to encode digital data into a data representation that can be directly recorded in some specified optical storage medium. We would also like to draw attention to related publications by Neifield [4,5], where the information capacity of pixelated diffractive Fourier elements is examined considering a certain sparse multivalued encoding of data. However, this approach is based on statistical simulation studies and does not take advantage of information-theoretical methods.…”