1. Department of Physics, Indian Institute of Technology Roorkee, Roorkee, India
2. Bayer Crop Science, Creve Coeur, MO, USA
3. Micro and Nano Optics Centre, CSIR-Central Scientific Instruments Organisation, Chandigarh, India
4. Department of Physics and the Center for Photonics and Quantum Communication Technology, Indian Institute of Technology Roorkee, Roorkee, India