1. Department of PhysicsIndian Institute of TechnologyGuwahati‐781039, AssamIndia
2. Department of PhysicsUniversity of Puerto RicoSan Juan, PR 00936‐8377USA
3. UGC‐DAE Consortium for Scientific ResearchUniversity CampusIndore 452 017India
4. Department of Photonics and Display InstituteNational Chiao Tung UniversityHsinchuTaiwan‐30010, ROC