Abstract

The prospects for gray-scale (or multilevel) digital holographic data storage are theoretically and experimentally investigated. A simple signal-to-noise ratio (SNR) partitioning argument shows that when SNR scales as 1 over the number of holograms squared, five gray levels log2 5 bits/pixel would be expected to result in a 15% capacity increase over binary data pages. However, the additional signal-dependent noise sources present in practical systems create a baseline SNR that reduces both the optimal number of gray levels and the resulting gain in capacity. To implement gray-scale recording experimentally, we adapt the predistortion technique previously developed for binary page-oriented memories [Opt.  Lett. 23, 289 (1998)]. Several new block-based modulation codes for decoding gray-scale data pages are introduced. User capacity is evaluated by an experimental technique using LiNbO3:Fe in the 90° geometry. Experimental results show that a balanced modulation code with three gray levels provides a 30% increase in capacity (as well as a 30% increase in readout rate) over local binary thresholding.

© 1998 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. D. Psaltis and F. Mok, Sci. Am. 273(5), 70 (1995).
    [CrossRef]
  2. J. F. Heanue, M. C. Bashaw, and L. Hesselink, Science 265, 749 (1994).
    [CrossRef] [PubMed]
  3. J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
    [CrossRef]
  4. J. F. Heanue, K. Gurkan, and L. Hesselink, Appl. Opt. 35, 2431 (1996).
    [CrossRef] [PubMed]
  5. M. A. Neifeld and M. McDonald, Opt. Lett. 19, 1483 (1994).
    [CrossRef] [PubMed]
  6. G. W. Burr, J. Ashley, H. Coufal, R. K. Grygier, J. Hoffnagle, C. M. Jefferson, and B. Marcus, Opt. Lett. 22, 639 (1997).
    [CrossRef] [PubMed]
  7. J. F. Heanue, M. C. Bashaw, and L. Hesselink, J. Opt. Soc. Am. A 12, 2432 (1995).
    [CrossRef]
  8. G. W. Burr, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, Opt. Lett. 23, 289 (1998).
    [CrossRef]
  9. G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).
  10. D. Psaltis, D. Brady, and K. Wagner, Appl. Opt. 27, 1752 (1988).
    [CrossRef]

1998 (1)

1997 (1)

1996 (1)

1995 (3)

J. F. Heanue, M. C. Bashaw, and L. Hesselink, J. Opt. Soc. Am. A 12, 2432 (1995).
[CrossRef]

D. Psaltis and F. Mok, Sci. Am. 273(5), 70 (1995).
[CrossRef]

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

1994 (2)

M. A. Neifeld and M. McDonald, Opt. Lett. 19, 1483 (1994).
[CrossRef] [PubMed]

J. F. Heanue, M. C. Bashaw, and L. Hesselink, Science 265, 749 (1994).
[CrossRef] [PubMed]

1988 (1)

Ashley, J.

Bashaw, M. C.

Brady, D.

Burr, G. W.

G. W. Burr, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, Opt. Lett. 23, 289 (1998).
[CrossRef]

G. W. Burr, J. Ashley, H. Coufal, R. K. Grygier, J. Hoffnagle, C. M. Jefferson, and B. Marcus, Opt. Lett. 22, 639 (1997).
[CrossRef] [PubMed]

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Chang, T. Y.

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Chou, W.-C.

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Christian, W.

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Coufal, H.

G. W. Burr, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, Opt. Lett. 23, 289 (1998).
[CrossRef]

G. W. Burr, J. Ashley, H. Coufal, R. K. Grygier, J. Hoffnagle, C. M. Jefferson, and B. Marcus, Opt. Lett. 22, 639 (1997).
[CrossRef] [PubMed]

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Grygier, R. K.

Gurkan, K.

Heanue, J. F.

Hesselink, L.

Hoffnagle, J.

Hoffnagle, J. A.

G. W. Burr, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, Opt. Lett. 23, 289 (1998).
[CrossRef]

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Hong, J. H.

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Jefferson, C. M.

G. W. Burr, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, Opt. Lett. 23, 289 (1998).
[CrossRef]

G. W. Burr, J. Ashley, H. Coufal, R. K. Grygier, J. Hoffnagle, C. M. Jefferson, and B. Marcus, Opt. Lett. 22, 639 (1997).
[CrossRef] [PubMed]

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Marcus, B.

McDonald, M.

McMichael, I.

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Mok, F.

D. Psaltis and F. Mok, Sci. Am. 273(5), 70 (1995).
[CrossRef]

Neifeld, M. A.

M. A. Neifeld and M. McDonald, Opt. Lett. 19, 1483 (1994).
[CrossRef] [PubMed]

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Paek, E. G.

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Psaltis, D.

Wagner, K.

Appl. Opt. (2)

J. Opt. Soc. Am. A (1)

Opt. Eng. (1)

J. H. Hong, I. McMichael, T. Y. Chang, W. Christian, and E. G. Paek, Opt. Eng. 34, 2193 (1995).
[CrossRef]

Opt. Lett. (3)

Sci. Am. (1)

D. Psaltis and F. Mok, Sci. Am. 273(5), 70 (1995).
[CrossRef]

Science (1)

J. F. Heanue, M. C. Bashaw, and L. Hesselink, Science 265, 749 (1994).
[CrossRef] [PubMed]

Other (1)

G. W. Burr, W.-C. Chou, M. A. Neifeld, H. Coufal, J. A. Hoffnagle, and C. M. Jefferson, “Experimental evaluation of user capacity in holographic data storage systems,” Appl. Opt. (to be published).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (3)

Fig. 1
Fig. 1

Normalized capacity as a function of gray level g. For the solid curve, SNR drops as 1 over the number of holograms squared. The dashed curves indicate the effect when signal-dependent noise sources increase in importance relative to the background noise floor, as quantified by the ratio between the initial and the final SNR.

Fig. 2
Fig. 2

Histogram of six-level hologram recorded in the IBM DEMON system by use of the predistortion technique.8

Fig. 3
Fig. 3

Capacity rdetectrECCM versus readout rate rdetectrECC for modulation codes and the min–max thresholding method at varying numbers of gray levels g. Each curve indicates a range of choices of 8-bit/symbol Reed–Solomon codes, progressing left to right from stronger to weaker codes; the symbols indicate the maximum capacity points.

Tables (1)

Tables Icon

Table 1 Gray-Scale Decoders

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

SNR=1g-1i=0g-2μi+1-μiσi+12+σi2

Metrics