Study of the effect of director fluctuations on liquid-crystalline molecular reorientation

• Autorzy: Sierakowski, M. W.
• Języki publikacji: EN

Abstrakty

EN

Initial phase of field-induced molecular reorientation in threshold geometry of a liquid-crystalline structure is essentially influenced by thermal orientational fluctuations. Still not quite clear is the way in which the reorientation starts and how it runs over an LC-structure in its initial phase. Fluctuations are stochastic events in time and also in space. This feature suggests, that the reorientation process may be induced by director fluctuations locally in a particular part of the LC-structure. In this work we have studied the impact of fluctuations on the molecular reorientation in nematics involving optical nonlinear interaction. The restricted area of a nematic layer was excited by light beam that amplified director fluctuations locally. By manipulation of optical excitation we were able to affect the dynamics of the effect. Since the threshold-type configuration of nematics is used in a number of optical devices, the obtained results may have practical aspect contributing to a new way of controlling the field-induced transition.

Słowa kluczowe

EN

liquid crystals; molecular reorientation; director fluctuations; optical nonlinearity

• Czasopismo: Opto-Electronics Review
• Rocznik: 2014
• Tom: Vol. 22, No. 2
• Strony: 109-112
• Opis fizyczny: Bibliogr. 8 poz., wykr.

Twórcy

autor

Sierakowski, M. W.

• Faculty of Physics, Warsaw University of Technology, 75 Koszykowa Str., 00-662 Warsaw, Poland,

Bibliografia

• 1. P.G. de Gennes, The Physics of Liquid Crystals, Clarendon, Oxford Press, 1974.
• 2. S. Chandrasekhar, Liquid Crystals,2nd edition, Cambridge University Press, Cambridge, 1992.
• 3. P. Oswald and P. Pieranski, Nematic and Cholesteric Liquid Crystals, Taylor & Francis, London, 2005.
• 4. I.C. Khoo, Liquid Crystals,2nd edition, Wiley, New York, 2007.
• 5. M.W. Sierakowski, “The orientational fluctuations in the reorientation process of a nematic liquid crystal”, Mol. Cryst. Liq. Cryst. 544, 192 [1180]–202 [1190] (2011).
• 6. D. Andrienko, G. Germano, and M.P. Allen, “Liquid crystal director fluctuations and surface anchoring by molecular simulation”, Phys. Rev. E 62 (5 Pt B), 6688–6693 (2000).
• 7. V.P. Romanov and G. K. Sklyarenko, “Fluctuations in nematics near Freedericksz and flexoelectric transitions”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 158, 355–361 (1999).
• 8. S. Dhara and N.V. Madhusudana, “Influence of director fluctuations on the electric-field phase diagrams of nematic liquid crystals”, Europhys. Lett. 67, 411–417 (2004).

Identyfikatory

DOI

10.2478/s11772-014-0185-z