1. Centre for Research in Nanoscience & Nanotechnology; University of Calcutta, Block-JD-2, Sector-III, Salt Lake; Kolkata- 700106
2. Department of Physics; National University of Singapore; 2 Science Drive 3, Blk S12 Singapore 117551
3. Department of Applied Optics and Photonics; University of Calcutta, Block-JD-2, Sector-III, Salt Lake; Kolkata- 700106
4. S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake; Kolkata- 700106