1. Photonic Networks and Technologies Lab, CNIT, Via G. Moruzzi 1, 56124 Pisa, Italy
2. INPHOTEC, Via G. Moruzzi 1, 56124 Pisa, Italy
3. Center for Nanotechnology Innovation @NEST - Istituto Italiano di Tecnologia, Piazza San Silvestro 12, I-56127 Pisa, Italy
4. Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
5. NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, I-56127 Pisa, Italy
6. Photonic Networks and Technologies Lab, Tecip Institute, Scuola Superiore Sant’Anna, Via G. Moruzzi 1, 56124 Pisa, Italy
7. Cambridge Graphene Centre, Cambridge University, 9 J.J. Thompson, Cambridge, U.K.
8. CamGraPhiC, Via Moruzzi 1, 56124 Pisa, Italy