1. Vivekanand (P.G.) College, Manendragarh, Chhattisgarh, India
2. Department of Applied physics, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh, India
3. Department of Physics, Banaras Hindu University, Varanasi, Uttar Pradesh, India
4. Department of Physics, Govt. V.Y.T. P.G. College, Durg, Chhattisgarh, India
5. Liquid Crystal Laboratory, University of Lucknow, Lucknow, Uttar Pradesh, India