1. Dept. of Physics, Krishna University, Machilipatnam, Andhra Pradesh, India
2. Department of Physics, A. L. College, Vijayawada, Andhra Pradesh, India
3. Liquid Crystal Research Centre, Department of Electronics and Communications Engineering, K. L. University, Vaddeswaram, Andhra Pradesh, India
4. SD Technical Specialities, Machilipatnam, Andhra Pradesh, India