Abstract
Wave equation for optical waves in the incommensurate phase of Rb2ZnCl4-type crystals is solved taking into account spatial dependence of optical permittivities due to incommensurate modulation of the lattice. Using the procedure originally proposed by Golovko and Levanyuk it is shown that for the wave vectors parallel to the orthorhombic axes: a) the waves are not purely transverse, b) their amplitudes are spatially modulated and c) their velocities are changed so that corrections to refractive indices exist due to permittivity modulation. Data on birefringence of Rb2ZnCl4 are analysed and it is shown that these corrections are responsible for the jump-like changes of refractive indices at the incommensurate-ferroelectric phase transition, together with the quasi-discontinuous change of the order parameter modulus. The spatial variance of the wave amplitudes may be responsible for the possibility of SHG in the incommensurate phase whose averaged point group is centrosymmetric.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Gehring G. A.: J. Phys. C — Solid State Phys.10 (1977) 531.
Fousek J., Petzelt J.: Phys. Status Solidi (a)55 (1979) 11.
Ivanov N. R.: Izv. Akad. Nauk SSSR, Ser. Fiz.47 (1983) 450.
Sannikov D. G., Levanyuk A. P.: Fiz. Tverd. Tela20 (1978) 1005.
Sannikov D. G., Golovko V. A.: Fiz. Tverd. Tela26 (1984) 1147.
Kroupa J., Fousek J., Smutný F., Březina B.: Phys. Status Solidi (b)113 (1982) K 153.
Melnikova S. V., Anistratov A. T.: Fiz. Tverd. Tela25 (1983) 848.
Régis M., Ribet J. L., Jamet J. P.: J. Phys. Lett. (France)43 (1982) L 333.
Vlokh O. G., Kityk A. V., Polovinko I. I.: Kristallografiya29 (1984) 1198.
Kudo S., Ikeda T.: J. Phys. Soc. Jap.50 (1981) 3681.
Koňák Č., Matras J.: Czech. J. Phys. B26 (1976) 577.
Gomez-Cuevas A., Tello M. J., Fernandez J., Lopez-Echarri A., Herreros J., Couzi M.: J. Phys. C — Solid State Phys.16 (1983) 473.
Golovko V. A., Levanyuk A. P.: Zh. Eksp. Teor. Fiz.77 (1979) 1556.
Kroupa J., Fousek J.: Jap. J. Appl. Phys.24 (1985) Suppl. 24-2, 787.
Günter P., Sanctuary R., Rohner F.: Phys. Status Solidi (a)70 (1982) 583.
Sanctuary R., Jundt D., Baumert J.-C., Günter P.: Phys. Rev. B32 (1985) 1649.
Errandonéa G., Tolédano J. C., Litzler A., Savary H., Schneck J., Aubrée J.: J. Phys. Lett. (Paris)45 (1984) L 329.
Saint-Grégoire P., Schäfer F. J., Kleemann W., Durand J., Goiffon A.: J. Phys. C — Solid State Phys.17 (1984) 1375.
Jamet J. P.: J. Phys. Lett. (Paris)42 (1981) L 123.
Author information
Authors and Affiliations
Additional information
The authors gratefully acknowledge helpful discussions with Dr. V. Dvořák.
Rights and permissions
About this article
Cite this article
Fousek, J., Kroupa, J. Propagation of light in Rb2ZnCl4-type crystals with incommensurate modulation. Czech J Phys 36, 1192–1202 (1986). https://doi.org/10.1007/BF01959610
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01959610