1. Institute for Research in Electronics and Applied Physics and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
2. Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20740, United States
3. Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
4. Photonic Inc., Coquitlam, BC V3K 6T1, Canada