¹1 Photonics Initiative, Advanced Science Research Center, City University of New York, New York City, NY 10031, USA

²2 Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712, USA

³3 Electrical Engineering Institute, École Polytechnique Fedérale de Lausanne (EPFL), CH-1015 Lausanne Switzerland

⁴4 Naval Surface Warfare Center Carderock Division, West Bethesda, MD 20817 USA

⁵5 Physics Program, Graduate Center, City University of New York, New York City, NY 10026, USA

⁶6 Department of Electrical Engineering, City College of New York, New York City, NY 10031, USA