Temperature effect on the refractive indices and Kerr constant of doped nematic liquid crystals with right-handed dopants

Document Type : Full length research Paper

Author

Department of Laser and Optical Engineering, University of Bonab, Bonab, Iran

Abstract

Liquid crystals with high optical and electro-optical responses play an important role in optics and photonics. Therefore, providing a simple method to increase the optical behavior of liquid crystals under the influence of external fields can be considered one of the most challenging research areas. In this experimental work, the effects of temperature and right-handed chiral material with different weight percentages on the refractive indices and optical properties of E7 nematic liquid crystal under the influence of an external electric field were investigated. Despite the reduction of the Kerr constant with increasing the weight percentage of chiral dopants and temperature, the highest amount of optical response in the presence of the electric field was obtained for the nematic liquid crystal doped with 3% of right-handed material. In this case, the value of the Kerr constant is almost 2 times that of pure liquid crystal. This interesting result can be related to the order parameter changes caused by different molecular interactions. Thus, the results obtained in this research can be used as a simple method to increase the optical response of nematic liquid crystals in the presence of an external electric field.

Keywords

Main Subjects


 
[1] I.C. Khoo, Liquid crystals, John Wiley & Sons, 2022.
[2] P. Raynes, Liquid Crystals, Second Edition, Cambridge University Press, 1992.
[3] S. Gauz, X. Zhu, W. Piecek, R. Dabrowski, S.T. Wu, Fast Switching Liquid Crystals for Color-Sequential LCDs, Journal of Display Technology, 3 (2007) 250-252. https://doi.org/10.1109/JDT.2007.900909
[4] A. Hussain, A.S. Pina, A.C.A. Roque, Bio-recognition and detection using liquid crystals, Biosensors and Bioelectronics, 25 (2009) 1-8. https://doi.org/10.1016/j.bios.2009.04.038
[5] S.E. Robinson, B.A. Grinwald, L.L. Bremer, K.A. Kupcho, B.R. Acharya, P.D. Owens, A Liquid Crystal-Based Passive Badge for Personal Monitoring of Exposure to Hydrogen Sulfide, Journal of Occupational and Environmental Hygiene, 11 (2014) 741-750. https://doi.org/10.1080/15459624.2014.916808
[6] O. Pishnyak, S. Sato, O.D. Lavrentovich, Electrically tunable lens based on a dual-frequency nematic liquid crystal, Applied Optics, 45 (2006) 4576-4582.  https://doi.org/10.1364/AO.45.004576
[7] H.V.J. Masterson, G.D. Sharp, K.M. Johnson, Ferroelectric liquid-crystal tunable filter, Optics Letters, 14 (1989) 1249-1251. https://doi.org/10.1364/OL.14.001249
[8] P. Kumar, S.W. Kang, S.H. Lee, Advanced bistable cholesteric light shutter with dual frequency nematic liquid crystal. Optical Materials Express, 2 (2012) 1121-1134. https://doi.org/10.1364/OME.2.001121
[9] M. Mitov, Cholesteric Liquid Crystals with a Broad Light Reflection Band, Advanced materials, 24 (2012) 6260-6276. https://doi.org/10.1002/adma.201202913
[10] H. Khandelwal, A.P. Schenning, M.G. Debije, Infrared regulating smart window based on organic materials, Advanced Energy Materials, 7 (2017) 1602209. https://doi.org/10.1002/aenm.201602209
[11] A. Maleki, M.H. Majles Ara, Z. Mousavi, M. Rafiee, Z. Dehghani, S. Mohajer, Electro-optical Kerr effect of azo-dye-doped liquid crystals using nulled intensity method, Phase Transi tions, 2016. 89 (2016) 1137-1145. https://doi.org/10.1080/01411594.2016.1150472
[12] S. Kiani, M. Zakerhamidi, H. Tajalli, Hydrogen bonding intermolecular effect on electro-optical response of doped 6PCH nematic liquid crystal with some azo dyes, Optical Materials, 55 (2016) 121-129. https://doi.org/10.1016/j.optmat.2016.03.019
[13] S. Friberg, P. Smith, Nonlinear optical glasses for ultrafast optical switches, IEEE journal of quantum electronics, 23 (1987) 2089-2094. https://doi.org/10.1109/JQE.1987.1073278
[14] M. Khadem Sadigh, M. Zakerhamidi, Third order nonlinear responses of Basic Blue 55 molecules in polar solvents, Optik, 130 (2017) 743-749. https://doi.org/10.1016/j.ijleo.2016.10.134
[15] M. Khadem Sadigh, M. Zakerhamidi, Media polarity and concentration roles on the third order nonlinear behaviors of thiazine dyes, Optics & Laser Technology, 100 (2018) 216-224. https://doi.org/10.1016/j.optlastec.2017.10.007
[16] M. Khadem Sadigh, M.S. Zakerhamidi, B. Rezaer, K. Milanchian, Environment effects on the nonlinear absorption properties of Methylene blue under different power of excitation beam. Journal of Molecular Liquids, 229 (2017) 548-554. https://doi.org/10.1016/j.molliq.2016.12.108
[17] H. Khoshsima, H. Tajalli, A. Ghnadzadeh Gilani, R. Dabrowski, Electro-optical Kerr effect of two high birefringence nematic liquid crystals. Journal of Physics D: Applied Physics, 39 (2006) 1495. https://doi.org/10.1088/0022-3727/39/8/007.
[18] M. Fiaz, M. Beevers, Kerr constant of poly (N-vinylcarbazole), European Polymer Journal, 36 (2000) 1943-1950. https://doi.org/10.1016/S0014-3057(99)00248-7
[19] A.G. Gilani, H. Tajalli, E. Vahedi, Kerr effect studies on mixtures of the two tolane base liquid crystals, Molecular Crystals and Liquid Crystals, 502 (2009) 99-108. https://doi.org/10.1080/15421400902815795.
[20] M.S. Beevers, G. Khanarian, Measurement of Kerr constants of conducting liquids, Australian Journal of Chemistry, 32 (1979) 263-269. https://doi.org/10.1071/CH9790263
[21] A. Ranjkesh, S. kiani, O. Strzezysz, M.S. Zakerhamidi, T.H, Yoon, Optical anisotropy, order parameter and its critical behavior in temperature-dependent refractive indices of nematic liquid crystals, Journal of Molecular Liquids, 268 (2018) 536-544. https://doi.org/10.1016/j.molliq.2018.07.089
[22] M. Khadem Sadigh, P. Naziri, M.S. Zakerhamidi, A. Ranjkesh, T.H. Yoon, Temperature dependent features of polymer stabilized cholesteric liquid crystals based on selected liquid crystal characteristics, Optik, 230 (2021) 166354. https://doi.org/10.1016/j.ijleo.2021.166354
[23] M. Khadem Sadigh, P. Naziri, A. Ranjkesh, M.S. Zakerhamidi, Relationship of pitch length of cholesteric liquid crystals with order parameter and normalized polarizability, Optical Materials, 119 (2021) 111373. https://doi.org/10.1016/j.optmat.2021.111373
[24] A. Ranjkeh, Z. Alipanah, S. Kiani, M.S. Zkerhamidi, T.H. Yoon, A method to find the initial temperature range of the short-range order in the isotropic phase of nematic liquid crystals based on the electro-optical Kerr effect. Journal of Molecular Liquids, 274 (2019) 646-652. https://doi.org/10.1016/j.molliq.2018.11.028
[25] M. Khadem Sadigh, M.S. Zakerhamidi, A. Ranjkesh, Enhanced electro-optical nonlinear responses of doped nematic liquid crystals: Towards optoelectronic devices, Optics and Lasers in Engineering, 159 (2022) 107229. https://doi.org/10.1016/j.optlaseng.2022.107229
[26] M. Khadem Sadigh, A. Ranjkesh, B. Hayatifar, Improving the nonlinear electro-optical responses of doped nematic liquid crystals with chiral dopants, Optical Materials, 135 (2023) 113352. https://doi.org/10.1016/j.optmat.2022.113352