1. Department of Electrical and Electronics Engineering and the Physics Department, Birla Institute of Technology and Science, Pilani, Hyderabad, Telangana, India
2. Department of Electronics and Communication Engineering, Vignana Bharathi Institute of Technology, Hyderabad, Telangana, India
3. Physics Department, Birla Institute of Technology and Science, Pilani, Hyderabad, Telangana, India