TY - JOUR
T1 - Mapping the electromagnetic field confinement in the gap of germanium nanoantennas with plasma wavelength of 4.5 micrometers
AU - Calandrini, Eugenio
AU - Venanzi, Tommaso
AU - Appugliese, Felice
AU - Badioli, Michela
AU - Giliberti, Valeria
AU - Baldassarre, Leonetta
AU - Biagioni, Paolo
AU - De Angelis, Francesco
AU - Klesse, Wolfgang M.
AU - Scappucci, Giordano
AU - Ortolani, Michele
PY - 2016/9/19
Y1 - 2016/9/19
N2 - We study plasmonic nanoantennas for molecular sensing in the mid-infrared made of heavily doped germanium, epitaxially grown with a bottom-up doping process and featuring free carrier density in excess of 1020 cm-3. The dielectric function of the 250 nm thick germanium film is determined, and bow-tie antennas are designed, fabricated, and embedded in a polymer. By using a near-field photoexpansion mapping technique at λ = 5.8 μm, we demonstrate the existence in the antenna gap of an electromagnetic energy density hotspot of diameter below 100 nm and confinement volume 105 times smaller than λ3.
AB - We study plasmonic nanoantennas for molecular sensing in the mid-infrared made of heavily doped germanium, epitaxially grown with a bottom-up doping process and featuring free carrier density in excess of 1020 cm-3. The dielectric function of the 250 nm thick germanium film is determined, and bow-tie antennas are designed, fabricated, and embedded in a polymer. By using a near-field photoexpansion mapping technique at λ = 5.8 μm, we demonstrate the existence in the antenna gap of an electromagnetic energy density hotspot of diameter below 100 nm and confinement volume 105 times smaller than λ3.
UR - http://resolver.tudelft.nl/uuid:96f50a44-5005-47e9-a782-e1d48e766fc4
UR - http://www.scopus.com/inward/record.url?scp=84988499108&partnerID=8YFLogxK
U2 - 10.1063/1.4962976
DO - 10.1063/1.4962976
M3 - Article
AN - SCOPUS:84988499108
SN - 0003-6951
VL - 109
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 12
M1 - 121104
ER -