title: Luo et al. Reply.
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.|Centre for OptoElectronics and Biophotonics, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue 639798, Singapore.
authors.forename: Yu
authors.initials: Y
authors.lastname: Luo
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.|Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, E-28049 Madrid, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Fernandez-Dominguez
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Aeneas
authors.initials: A
authors.lastname: Wiener
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: J B
authors.initials: JB
authors.lastname: Pendry