1. Department of Nanophotonics and Metamaterials, ITMO University, St. Petersburg 197101, Russia
2. Nonlinear Physics Centre, Australian National University, Canberra, ACT 2601, Australia
3. Department of Electrical Engineering, Grove School of Engineering, The City College of the City University of New York, 140th Street and Convent Avenue, New York, New York 10031, USA
4. Graduate Center of the City University of New York, New York, New York 10016, USA
5. Microelectronics Research Centre, Cockrell School of Engineering, University of Texas at Austin, Austin, Texas 78758, USA