title: Surface plasmon lasing observed in metal hole arrays.
abstract: Surface plasmons in metal hole arrays have been studied extensively in the context of extraordinary optical transmission, but so far these arrays have not been studied as resonators for surface plasmon lasing at optical frequencies. We experimentally study a metal hole array with a semiconductor (InGaAs) gain layer placed in close (20 nm) proximity of the metal hole array. As a function of increasing pump power, we observe an intense and spectrally narrow peak, with a clear threshold. This laser emission is donut shaped and radially polarized. Three experimental observations support that the system shows surface plasmon lasing. First, the full wavelength dispersion of the observed resonances can be understood by using a single surface plasmon mode of the system. Second, the polarization of these resonances is as expected for surface plasmons. Third, the magnitude of the avoided crossing, which results from mode coupling at the holes, has a similar magnitude as found in simulations using surface plasmons.
authors.affiliation: Leiden University, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, Netherlands.
authors.forename: Frerik
authors.initials: F
authors.lastname: van Beijnum
authors.affiliation: COBRA Research Institute, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven, Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: van Veldhoven
authors.affiliation: COBRA Research Institute, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven, Netherlands.
authors.forename: Erik Jan
authors.initials: EJ
authors.lastname: Geluk
authors.affiliation: Leiden University, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, Netherlands.
authors.forename: Michiel J A
authors.initials: MJ
authors.lastname: de Dood
authors.affiliation: Leiden University, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, Netherlands and Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven, Netherlands.
authors.forename: Gert W
authors.initials: GW
authors.lastname: 't Hooft
authors.affiliation: Leiden University, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, Netherlands.
authors.forename: Martin P
authors.initials: MP
authors.lastname: van Exter