1. Department of Physics, Lekshmipuram College of Arts and Science, Neyyoor, Affiliated to Manonmaniam Sundaranar University, Tirunelveli, India
2. Department of Physics, S. T. Hindu College, Nagercoil, Affiliated to Manonmaniam Sundaranar University, Tirunelveli, India
3. Department of Physics, University College of Engineering, Anna University, BIT Campus, Tiruchirappalli, India