1. Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA
2. Center of Advanced Studies in Photonics Research (CASPR), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA
3. Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA