2 research outputs found
Exploring Light–Matter Interaction Phenomena under Ultrastrong Coupling Regime
Exciton-polaritons are bosonic quasiparticles
that arise from the normal mode splitting of photons in a microcavity
and excitons in a semiconductor material. One of the most intriguing
extensions of such a light–matter interaction is the so-called
ultrastrong coupling regime. It is achieved when the Rabi frequency
(Ω<sub>R</sub>, the energy exchange rate between the emitter
and the resonant photonic mode) reaches a considerable fraction of
the emitter transition frequency, ω<sub>0</sub>. Here, we report
a Rabi energy splitting (2ℏΩ<sub>R</sub>) of 1.12 eV
and record values of the coupling ratio (2Ω<sub>R</sub>/ω<sub>0</sub>) up to 0.6-fold the material band gap in organic semiconductor
microcavities and up to 0.5-fold in monolithic heterostructure organic
light-emitting diodes working at room temperature. Furthermore, we
show that with such a large coupling strength it is possible to undress
the exciton homogeneous linewidth from its inhomogeneous broadening,
which allows for an unprecedented narrow emission line (below the
cavity finesse) for such organic LEDs. The latter can be exploited
for the realization of novel monochromatic sources and near-IR organic
emitting devices
Mid-Infrared Plasmonic Excitation in Indium Tin Oxide Microhole Arrays
Transparent
conducting oxides (TCOs) are emerging as possible alternative
constituent materials to replace noble metals such as silver and gold
for low-loss plasmonic applications in the near-infrared (NIR) and
mid-infrared (MIR) regimes. In particular, TCO-based nanostructures
are extensively investigated for biospectroscopy exploiting their
surface-enhanced infrared absorption (SEIRA). The latter enhances
the absorption from vibrational and rotational modes of nearby biomolecules,
making TCO nanostructures a promising candidate for IR sensing applications.
Nevertheless, in order to produce inexpensive devices for lab-on-a-chip
diagnostics, it would be favorable to achieve surface-enhanced infrared
absorption with very simple microstructures not requiring nanosize
control. In this work, we attempt to demonstrate a SEIRA effect with
the least challenging fabrication, ÎĽm-scale instead of nm-scale,
by tailoring both device design and charge density of the indium tin
oxide (ITO) film. We show that microperiodic hole arrays in a ITO
film are able to produce SEIRA via grating coupling. Such a study
opens the way for innovative and disrupting biosensing devices