Bowtie plasmonic quantum cascade laser antenna.
We report a bowtie plasmonic quantum cascade laser antenna that can confine coherent mid-infrared radiation well below the diffraction limit. The antenna is fabricated on the facet of a mid-infrared quantum cascade laser and consists of a pair of gold fan-like segments, whose narrow ends are separated by a nanometric gap. Compared with a nano-rod antenna composed of a pair of nano-rods, the bowtie antenna efficiently suppresses the field enhancement at the outer ends of the structure, making it more suitable for spatially-resolved high-resolution chemical and biological imaging and spectroscopy. The antenna near field is characterized by an apertureless near-field scanning optical microscope; field confinement as small as 130 nm is demonstrated at a wavelength of 7.0 mum.
Yu
Nanfang
N
Cubukcu
Ertugrul
E
Diehl
Laurent
L
Bour
David
D
Corzine
Scott
S
Zhu
Jintian
J
Höfler
Gloria
G
Crozier
Kenneth B
KB
Capasso
Federico
F