Functional optoelectronic nanomaterials

We focus on low-dimensional nanostructures that support localized surface plasmon resonances in the wide range of frequencies (from UV to IR) to use them in the studies of fundamental nanophotonics and in a broad range of applications. We like self-assembly-based nanofabrication and apply bottom-up nanofabrication methods to make impact in (bio)sensing, optical metamaterials, enhancement of various weak processes and many others.

Magnetoplasmonics

The brand new and rapidly developing field of magnetoplasmonics explores the mutual relation between magnetization and localized plasmons. So far it has been commonly believed that, despite the intrinsic presence of nanoplasmonic resonances in classical ferromagnetic materials as Ni, Co and Fe, they were exceedingly damped, due to high ohmic losses, to result in any appealing effects. In our research we demonstrate new and fundamental features of the nanostructured purely ferromagnetic materials - intrinsic plasmon-magnetization interplay.

J. Chen, P. Albella, Z. Pirzadeh, P. Alonso-González, F. Huth, S. Bonetti, V. Bonanni, J. Åkerman, J. Nogués, P. Vavassori, A. Dmitriev, J. Aizpurua and R. Hillenbrand.
Plasmonic Nickel Nanoantennas.
Small 7, 2341-2347 (2011).
DOI: 10.1002/smll.201100640

V. Bonanni, S. Bonetti, T. Pakizeh, Z. Pirzadeh, J. Chen, J. Nogués, P. Vavassori, R. Hillenbrand, J. Åkerman, and A. Dmitriev.
Designer magnetoplasmonics with nickel nanoferromagnets.
Nano Letters, Article ASAP (2011)
DOI: 10.1021/nl2028443
(news highlight in Institute of Physics’ (IOP) NanotechWeb, nanotechweb.org)

Engineering of Nanoplasmonic Resonances

Engineering of nanoplasmonic resonances

Basic nanoplasmonic resonances exist in a form of oscillating dipoles. These can be excited in various ways – from the far-field, in the near-field or even indirectly via light scattering of the neighbors. We engineer the ways to excite plasmons and their higher order modes (quadrupoles, for example) using optical spectroscopy and apertureless SNOM.

W. Khunsin, B. Brian, J. Dorfmüller, M. Esslinger, R. Vogelgesang, C. Etrich, C. Rockstuhl, A. Dmitriev and K. Kern.
Long-Distance Indirect Excitation of Nanoplasmonic Resonances.
Nano Letters 11, 2765-2769 (2011).
DOI: 10.1021/nl201043v

R. Vogelgesang and A. Dmitriev.
Real-space imaging of nanoplasmonic resonances (review).
Analyst, (2010).
DOI: 10.1039/c000887g

R. Esteban, R. Vogelgesang, J. Dorfmueller, A. Dmitriev, C. Rockstuhl, C. Etrich and K. Kern.
Direct Near-Field Optical Imaging of Higher Order Plasmonic Resonances.
Nano Lett. 8, 3155 (2008).
DOI: 10.1021/nl801396r

Enhanced Sensing

Refractometric sensing capability of surface-supported nanoplasmonic structures can be enhanced over the broad spectral range if one reduces the effect of the substrate - simply by positioning sensing nanostructures on small pillars.

K. Hedsten, J. Fonollosa, P. Enoksson, P. Modh, J. Bengtsson, D. S. Sutherland and A. Dmitriev.
Optical Label-Free Nanoplasmonic Biosensing Using a Vertical-Cavity Surface-Emitting Laser and Charge-Coupled Device.
Analytical Chemistry 82, 1535–1539 (2010).
DOI: 10.1021/ac9025169
(news feature in PhotonicsSpectra, http://www.photonics.com/Article.aspx?AID=41920)

A. Dmitriev, C. Hägglund, S. Chen, H. Fredriksson, T. Pakizeh, M. Käll and D. S. Sutherland.
Enhanced Nanoplasmonic Optical Sensors with Reduced Substrate Effect.
Nano Lett. 8, 3893 (2008).
DOI: 10.1021/nl8023142

Bottom-up Optical Metamaterials

Bottom-up optical metamaterials

Optical magnetism - i.e., induced magnetic dipole that oscillates with the frequency of light - can be engineered by combining two plasmonic nanostructures (gold nanodisks) in metal-dielectric-metal nanosandwich.

A. Mendoza-Galván, K. Järrendahl, A. Dmitriev, T. Pakizeh, M. Käll and H. Arwin.
Optical response of supported gold nanodisks.
Optics Express 19, 12093-12107 (2011).
DOI: 10.1364/OE.19.012093
(featured in the Virtual Journal for Biomedical Optics (VJBO), http://www.opticsinfobase.org/VJBO/virtual_issue.cfm?vid=144)

T. Pakizeh, A. Dmitriev, M. S. Abrishamian, N. Granpayeh and M. Käll
Structural asymmetry and induced optical magnetism in plasmonic nanosandwiches.
J. Opt. Soc. Am. B 25, 659 (2008).
DOI: 10.1364/JOSAB.25.000659
(featured in the Virtual Journal of Nanoscale Science & Technology)

A. Dmitriev, T. Pakizeh, M. Käll and D. S. Sutherland.
Gold–Silica–Gold Nanosandwiches: Tunable Bimodal Plasmonic Resonators.
Small 3, 294 (2007).
DOI: 10.1002/smll.200600409

Enhancing Weak Optical Processes: 'Lightening Up' Singlet Oxygen Radiative Decay

Enhancing weak optical processes

One of nature's most improbable transitions, radiative decay of singlet oxygen into triplet state, can be detected with the help of enhancing nanoplasmonic disks, tuned to the wavelength where emission happens.

R. Toftegaard, J. Arnbjerg, K. Daasbjerg, P. R. Ogilby, A. Dmitriev, D. S. Sutherland and L. Poulsen.
Metal-Enhanced 1270 nm Singlet Oxygen Phosphorescence.
Angew. Chem. Int. Ed. 47, 6025 (2008).
DOI: 10.1002/anie.200800755

Bottom-up Nanoplasmonics: Hole-mask Colloidal Lithography

Bottom-up nanoplasmonics

One of the most convenient ways to produce surface-supported arrays of nanoplasmonic structures is to use self-assembled colloidal nanoparticles as templates/masks. Various strategies in the same method produce arrays of metallic nanoellipses, metallic nanocones, bi-metallic nanodisks dimers and nanodisks embedded in a semiconductor.

H. Fredriksson, Y. Alaverdyan, A. Dmitriev, C. Langhammer, D. S. Sutherland, M. Zäch, and B. Kasemo.
Hole-mask colloidal lithography.
Adv. Mater. 19, 4297 (2007).
DOI: 10.1002/adma.200700680