title: Spectral collapse in ensembles of metamolecules.
abstract: We report on the first direct experimental demonstration of a collective phenomenon in metamaterials: spectral line collapse with an increasing number of unit cell resonators (metamolecules). This effect, which is crucial for achieving a lasing spaser, a coherent source of optical radiation fuelled by coherent plasmonic oscillations in metamaterials, is linked to the suppression of radiation losses in periodic arrays. We experimentally demonstrate spectral line collapse at microwave, terahertz and optical frequencies.
authors.affiliation: Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom. vaf@orc.soton.ac.uk
authors.forename: V A
authors.initials: VA
authors.lastname: Fedotov
authors.forename: N
authors.initials: N
authors.lastname: Papasimakis
authors.forename: E
authors.initials: E
authors.lastname: Plum
authors.forename: A
authors.initials: A
authors.lastname: Bitzer
authors.forename: M
authors.initials: M
authors.lastname: Walther
authors.forename: P
authors.initials: P
authors.lastname: Kuo
authors.forename: D P
authors.initials: DP
authors.lastname: Tsai
authors.forename: N I
authors.initials: NI
authors.lastname: Zheludev