Analysis and model of the photorefractive-like effect in non-conductive asymmetric liquid crystal hybrid cell

Abstract

In this paper we describe a non-conductive liquid crystal hybrid cell with the photoconductive polymer (PP) layer. The orientation of the liquid crystal (LC) molecules in the described optical device is controlled by an external electric field and proper illumination. Method to calculate photoinduced refractive index distribution in liquid crystal layer has been presented. We propose model of the space charge formation in photoconductive polymer layer in the presence of light. We assumed that the carriers generated by the light in the PP diffuse into unlighted area and drift in external field and local field of the generated charge. In determining the distribution of the space charge field, we take into account the field-induced charges on the borders of the individual layers. After calculation of the final distribution of space charge and proper field distribution, we determine the director field distribution and refractive index distribution in LC layer. Full Text: PDF References A. Walczak, E. Nowinowski-Kruszelnicki, "Waveguide couplers induced optically over organic junction", Opt. Eng. 47(3), 035402 (2008). CrossRef A. Walczak, "Electromagnetic wave beam self - guidance in liquid crystal - semiconductor cell", Phot. Lett. Poland 2(2), 73 (2010). CrossRef A. Brignon, I. Bongrand, B. Loiseaux, J.P. Huignard, "Signal-beam amplification by two-wave mixing in a liquid-crystal light valve", Opt. Lett. 22(24), 1855 (1997). CrossRef G. Cook, C.A. Wyres, M.J. Deer, D.C. Jones, "Hybrid organic-inorganic photorefractives", Liquid Crystals VII, SPIE Annual Meeting (2003). CrossRef F. Kajzar, S. Bartkiewicz, A. Miniewicz, "Optical amplification with high gain in hybrid-polymer–liquid-crystal structures", Appl. Phys. Lett. 74(20), 2924 (1999) CrossRef S. Bartkiewicz, K. Matczyszyn, A. Miniewicz, F. Kajzar, "High gain of light in photoconducting polymer–nematic liquid crystal hybrid structures", Opt. Commun. 187, 257 (2001). CrossRef M. Kaczmarek, A. Dyadyusha, S. Slussarenko, I.C. Khoo, "The role of surface charge field in two-beam coupling in liquid crystal cells with photoconducting polymer layers", J. Appl. Phys. 96, 2616 (2004). CrossRef P. Moszczyński, A. Walczak, P. Marciniak, "Model for simulation of photo-induced charges inside the hybrid LC cells", Phot. Lett. Poland 5(1), 11 (2013). CrossRef N. Kukhtarev, V. Markov, S. Odulov, M. Soskin, V. Vinetskii, "Holographic storage in electrooptic crystals. i. steady state", Ferroelectrics 22, 949 (1979). CrossRef N. Kukhtarev, T. Kukhtareva, "A unified treatment of radiation-induced photorefractive, thermal, and neutron transmutation gratings", IEEE Proceedings 87(11), 1857 (1999). CrossRef J.S. Schildkraut, Y. Cui, "Zero-order and first-order theory of the formation of space?charge gratings in photoconductive polymers", J. Appl. Phys. 72(11), 5055 (1992). CrossRef J.S. Schildkraut, A.V. Buettner, "Theory and simulation of the formation and erasure of space-charge gratings in photoconductive polymers", J. Appl. Phys. 72(5), 1888 (1992). CrossRef A. Twarowski, "Geminate recombination in photorefractive crystals", J. Appl. Phys. 65(7), 2833 (1989). CrossRef W.D. Gill, "Drift mobilities in amorphous charge-transfer complexes of trinitrofluorenone and poly-n-vinylcarbazole", J. Appl. Phys. 43(12), 5033 (1972). CrossRef A. Walczak, P. Moszczyński, E. Nowinowski-Kruszelnicki, "Semiconductor–LC Layer Boundary and Photonic Structures", Mol. Cryst. Liq. Cryst. 559(1), 186 (2012). CrossRef