Nature Publishing Group, publisher of Nature, and other science journals and reference works
Nature
my account e-alerts subscribe register
   
Friday 22 September 2017
Journal Home
Current Issue
AOP
Archive
Download PDF
References
Export citation
Export references
Send to a friend
More articles like this

Letters to Nature
Nature 384, 244 - 247 (21 November 1996); doi:10.1038/384244a0

Thermally stable nonlinear optical activity in a smectic-A liquid crystal

Hanlin Wang*, Moon Y. Jin, Richard C. Jarnagin*, Timothy J. Bunning§, Wade Adams, Brian Cull, Yushan Shi, Satyendra Kumar & Edward T. Samulski

*Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
High Performance Polymer Laboratory, KRICT, PO Box 107, Yuseong, Taejon 305-606, Korea
Materials Directorate, Wright Laboratory (WLyMLPJ), Wright-Patterson Air Force Base, Ohio 45433-6533, USA
§Science Applications International Corporation, 101 Woodman Drive, Suite 103, Dayton, Ohio 45431, USA
Department of Physics and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

THE key requirement for a material to exhibit nonlinear optical (NLO) activity is the presence of non-centrosymmetric (polar) order, an attribute that is usually restricted to certain crystalline classes and ferroelectric liquid crystals1,2. NLO activity can also be obtained in some amorphous organic materials by applying an intense electric field (corona discharge) above the glass transition temperature, T g, and subsequently quenching the field-induced polar orientation order3,4. Such materials are attractive for NLO device applications, as they promise lower costs and easier processibility than their crystalline organic and inorganic counterparts5. But field-induced polar order is not stable, and the eventual return to equilibrium (apolar) order results in a deterioration of NLO activity, particularly at temperatures near T g (refs 6, 7). Here we show that this thermally activated decay of polar order can be circumvented by using a liquid crystal in which both mesogens (molecules that induce a liquid-crystal phase) and NLO-active chromophores are appended to macromolecular siloxane rings. We find that a shear-aligned melt of these composite macromolecules gives rise to a material with a monodomain lamellar superstructure that retains bistable, field-induced polar order above T g. We attribute the thermal stability of these materials to an energetically favoured polar packing arrangement of the constituent macro-molecules.

  1. Chemla, D. S. & Zyss, J. (eds) Nonlinear Optical Properties of Organic Molecules and Crystals (Academic, Orlando, 1987).
  2. Schmidt, K. et al. Liq. Cryst. 14, 1735−1752 (1993).
  3. Singer, K. D., Sohn, J. E. & Lalama, S. J. Appl. Phys. Lett. 49, 248−250 (1986). | Article | ChemPort |
  4. Wu, J. et al. Appl. Phys. Lett. 58, 225−227 (1991). | Article | ChemPort |
  5. Marder, S. R. & Perry, J. W. Science 263, 1706−1707 (1994). | ChemPort |
  6. Burland, D. M., Miller, R. D. & Walsh, C. A. Chem. Rev. 94, 31 (1994). | Article | ChemPort |
  7. Verbiest, T. et al. Science 268, 1604−1608 (1995). | ChemPort |
  8. Walba, D. M. et al. Mol. Cryst. Liq. Cryst. 198, 51−60 (1991). | ChemPort |
  9. Benne, I., Semmler, K. & Finkelmann, H. Macromol. Rapid Commun. 15, 295−302 (1994). | ChemPort |
  10. Spes, P., Hessling, M. & Kreuzer, F.-H. US Patent No. 5231206 (1993).
  11. Bunning, T. J., Klei, H. E., Samulski, E. T., Crane, R. L., Linville, R. J. Liq. Cryst; 10, 445−456 (1991). | ChemPort |
  12. Bunning, T. J., Klei, H. E., Samulski, E. T., Adams, W. W. & Crane, R. L. Mol. Cryst. Liq. Cryst. 231, 163 (1993). | ChemPort |
  13. Cull, B., Shi, Y., Kumar, S., Shih, R. & Mann, J. Phys. Rev. E 51, 526−535 (1995). | Article | ChemPort |
  14. Wang, H., Jamagin, R. C. & Samulski, E. T. Macromolecules 27, 4705−4713 (1994). | Article | ChemPort |
  15. Marder, S. R. et al. Science 263, 511−514 (1994). | ChemPort |
  16. Lindsay, G. A., Henry, R. A., Hoover, J. M., Knoesen, A. & Mortazavi, M. A. Macromolecules 25, 4888−4894 (1992). | Article | ChemPort |
  17. Man, H. T. & Yoon, H. N. Adv. Mater. 4, 159−168 (1992). | Article | ChemPort |
  18. Singer, K. D. & King, L. A. J. Appl. Phys. 70, 3251−3255 (1991). | Article |
  19. Xu, B. & Swager, T. M. J. Am. Chem. Soc. 115, 1159−1160 (1993). | Article | ISI | ChemPort |
  20. Petschek, R. G. & Wiefling, K. M. Phys. Rev. Lett. 59, 343−346 (1987). | Article | PubMed | ChemPort |
  21. Perchak, D. R. & Petschek, R. G. Phys. Rev. A 43, 6756−6770 (1991). | Article | PubMed |
  22. Tournilhac, F. & Simon, J. Ferroelectrics 114, 283−287 (1991). | ChemPort |
  23. Tam, W., Guerin, B., Calbrese, J. C. & Stevenso, S. H. Chem. Phys. Lett. 154, 93−96 (1989). | Article | ChemPort |
  24. Bierlein, J. D., Cheng, L. K., Wang, Y. &Tarn, W. Appl. Phys. Lett. 56, 423−425 (1990). | Article | ChemPort |
  25. Bunning, T. J. thesis, Univ. Connecticut (1992).



© 1996 Nature Publishing Group
Privacy Policy