Non-volatile holographic storage in doubly doped lithium niobate crystals

Abstract

Photorefractive materials are being widely investigated for applications in holographic data storage1. Inhomogeneous illumination of these materials with an optical interference pattern redistributes charge, builds up internal electric fields and so changes the refractive index. Subsequent homogeneous illumination results in light diffraction and reconstructs the information encoded in the original interference pattern. A range of inorganic and organic photorefractive materials are known2, in which thousands of holograms of high fidelity can be efficiently stored, reconstructed and erased. But there remains a problem with volatility: the read-out process usually erases the stored information and amplifies the scattered light. Several techniques for ‘fixing’ holograms have been developed3,4,5,6, but they have practical disadvantages and only laboratory demonstrators have been built7,8,9,10. Here we describe a resolution to the problem of volatility that should lead to the realization of a more practical system. We use crystals of lithium niobate — available both in large size and with excellent homogeneity — that have been doped with two different deep electron traps (iron and manganese). Illumination of the crystals with incoherent ultraviolet light during the recording process permits the storage of data (a red-light interference pattern) that can be subsequently read, in the absence of ultraviolet light, without erasure. Our crystals show up to 32 per cent diffraction efficiency, rapid optical erasure of the stored data is possible using ultraviolet light, and light scattering is effectively prevented.

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Figure 1: Band diagram of LiNbO3 doped with iron (a) and doubly doped with iron and manganese (b).
Figure 2: Photo-assisted electron transfer between traps in doubly doped LiNbO3.
Figure 3: Holographic recording and read-out curves.
Figure 4: Recording and non-destructive read-out processes.

References

  1. 1

    Psaltis, D. & Mok, F. Holographic memories. Sci. Am. 273, 70–76 ((1995)).

    ADS  Article  Google Scholar 

  2. 2

    Meerholz, K., Volodin, B. L., Sandalphon, Kippele B. & Peyghambarian, N. Aphotorefractive polymer with high optical gain and diffraction efficiency near 100%. Nature 371, 497–500 (1994).

    ADS  CAS  Article  Google Scholar 

  3. 3

    Amodei, J. J. & Staebler, D. L. Holographic pattern fixing in electro-optic crystals. Appl. Phys. Lett. 18, 540–542 (1971).

    ADS  CAS  Article  Google Scholar 

  4. 4

    Micheron, F. & Bismuth, G. Electrical control of fixation and erasure of holographic patterns in ferroelectric materials. Appl. Phys. Lett. 20, 79–81 (1972).

    ADS  CAS  Article  Google Scholar 

  5. 5

    von der Linde, D., Glass, A. M. & Rodgers, K. F. Multiphoton photorefractive processes for optical storage in LiNbO3. Appl. Phys. Lett. 25, 155–157 (1974).

    ADS  CAS  Article  Google Scholar 

  6. 6

    Külich, H. C. Anew approach to read volume holograms at different wavelengths. Opt. Commun. 64, 407–411 (1987).

    ADS  Article  Google Scholar 

  7. 7

    Heanue, J. F., Bashaw, M. C., Daiber, A. J., Snyder, R. & Hesselink, L. Digital holographic storage system incorporating thermal fixing in lithium niobate. Opt. Lett. 21, 1615–1617 (1996).

    ADS  CAS  Article  Google Scholar 

  8. 8

    Ma, J. et al. Electrical fixing of 1000 angle-multiplexed holograms in SBN:75. Opt. Lett. 22, 1116–1118 (1997).

    ADS  CAS  Article  Google Scholar 

  9. 9

    Lande, D., Orlov, S. S., Akella, A., Hesselink, L. & Neurgaonkar, R. R. Digital holographic storage system incorporating optical fixing. Opt. Lett. 22, 1722–1724 (1997).

    ADS  CAS  Article  Google Scholar 

  10. 10

    Chuang, E. & Psaltis, D. Storage of 1000 holograms with use of a dual-wavelength method. Appl. Opt. 36, 8445–8454 (1997).

    ADS  CAS  Article  Google Scholar 

  11. 11

    Kurz, H. et al. Photorefractive centers in LiNbO3studied by optical, Mössbauer- and EPR-methods. Appl. Phys. 12, 355–368 (1977).

    ADS  CAS  Article  Google Scholar 

  12. 12

    Guenther, H., Wittmann, G., Macfarlane, R. M. & Neurgaonkar, R. R. Intensity dependence and white-light gating of two-color photorefractive gratings in LiNbO3. Opt. Lett. 22, 1305–1307 (1997).

    ADS  CAS  Article  Google Scholar 

  13. 13

    Staebler, D. L. & Phillips, W. Hologram storage in photochromic LiNbO3. Appl. Phys. Lett. 24, 268–270 (1974).

    ADS  CAS  Article  Google Scholar 

  14. 14

    Ming, Y., Krätzig, E. & Orlowski, R. Photorefractive effects in LiNbO3:Cr induced by two-step excitations. Phys. Status Solidi A 92, 221–229 (1985).

    ADS  Article  Google Scholar 

  15. 15

    Thiemann, O. & Schirmer, O. F. Energy levels of several 3d impurities and EPR of Ti3+ in LiNbO3. Proc. SPIE 1018, 18–22 (1988).

    ADS  Article  Google Scholar 

  16. 16

    Buse, K., Holtmann, L. & Krätzig, E. Activation of BaTiO3for infrared holographic recording. Opt. Commun. 85, 183–186 (1991).

    ADS  CAS  Article  Google Scholar 

  17. 17

    Mok, F. H., Burr, G. W. & Psaltis, D. System metric for holographic memory systems. Opt. Lett. 21, 896–898 (1996).

    ADS  CAS  Article  Google Scholar 

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Acknowledgements

We thank E. Krätzig for discussions. This work was supported by JPL, funded by DARPA/ITO, and by grants from Rome Labs. K.B. thanks the Deutsche Forschungsgemeinschaft for a postdoctoral fellowship.

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Correspondence to D. Psaltis.

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Buse, K., Adibi, A. & Psaltis, D. Non-volatile holographic storage in doubly doped lithium niobate crystals. Nature 393, 665–668 (1998). https://doi.org/10.1038/31429

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