1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2. Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
3. CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA
4. Materials Processing Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
5. Photonics Devices and Systems Group, Singapore University of Technology and Design, Singapore 487372, Singapore