en نانوفوتونیک و ساختارهای نانویی Nanophotonics and Nanostructures كاربردي Applicable <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-weight:bold">In this research the electro-optical Kerr effect of pure and doped nematic liquid crystal (NLC), E7, with different concentrations of SiO₂ nanoparticles were investigated at different temperatures. And the Kerr constant and pre-transitional behavior of the pure and doped samples experimentally were measured. The measurements indicate that Kerr constant varies inversely with temperature for all mixtures, which is in good agreement with Landau-De Gennes model. Also, induced birefringence versus the square value of applied voltage in three temperatures near the isotropic-nematic phase transition temperature were measured. The results imply that, the electro- optical response of liquid crystal increases by optimizing nanoparticle- liquid crystal composites. In the other words, the Kerr constant and induced birefringence of doped Liquid crystal increase by adding nanoparticles up to 0.07% wt.</span></span></span> Electro-Optics, Kerr effect, Liquid Crystal, SiO2 nanoparticles. 161 170 http://ijop.ir/browse.php?a_code=A-10-1027-1&slc_lang=en&sid=1 Batool Hayatifar bhayatifar@yahoo.com 10031947532846005348 10031947532846005348 Yes Aras International Campus, University of Tabriz, Tabriz, Iran Sohrab Ahmadi K. s_ahmadi@tabrizu.ac.ir 10031947532846005349 10031947532846005349 No Faculty of Physics, Tabriz University, Tabriz, Iran Mohammad Sadegh Zakerhamidi zakerhamidi@tabrizu.ac.ir 10031947532846005350 10031947532846005350 No Faculty of Physics, Tabriz University, Tabriz, Iran Mahsa Khadem Sadigh mahsa.sadigh@ubonab.ac.ir 10031947532846005351 10031947532846005351 No Department of Laser and Optics Engineering, Bonab University, Bonab, Iran