3 research outputs found
Metamaterial absorber integrated microfluidic terahertz sensors
Spatial overlap between the electromagnetic fields and the analytes is a key factor for strong light-matter interaction leading to high sensitivity for label-free refractive index sensing. Usually, the overlap and therefore the sensitivity are limited by either the localized near field of plasmonic antennas or the decayed resonant mode outside the cavity applied to monitor the refractive index variation. In this paper, by constructing a metal microstructure array-dielectric-metal (MDM) structure, a novel metamaterial absorber integrated microfluidic (MAIM) sensor is proposed and demonstrated in terahertz (THz) range, where the dielectric layer of the MDM structure is hollow and acts as the microfluidic channel. Tuning the electromagnetic parameters of metamaterial absorber, greatly confined electromagnetic fields can be obtained in the channel resulting in significantly enhanced interaction between the analytes and the THz wave. A high sensitivity of 3.5 THz/RIU is predicted. The experimental results of devices working around 1 THz agree with the simulation ones well. The proposed idea to integrate metamaterial and microfluid with a large light-matter interaction can be extended to other frequency regions and has promising applications in matter detection and biosensing
Multifunctional Silicon Optoelectronics Integrated with Plasmonic Scattering Color
Plasmonic
scattering from metallic nanoparticles has been used
for centuries to create the colorful appearance of stained glass.
Besides their use as passive spectral filtering components, multifunctional
optoelectronic applications can be achieved by integrating the nanoscatters
with semiconductors that generate electricity using the complementary
spectral components of plasmonic colors. To suppress the usual degradation
of both efficiency and the gamut of plasmonic scattering coloration
in highly asymmetric index configurations like a silicon host, aluminum
nanodisks on indium tin oxide (ITO) coated silicon were experimentally
studied and demonstrated color sorting in the full visible range along
with photocurrent generation. Interestingly, the photocurrents were
found to be comparable to the reference devices with only antireflection
coatings in spite of the power loss for coloration. Detailed investigation
shows that ITO serves as both the impedance matching layer for promoting
the backward scattering and schottky contact with silicon, and moreover,
plasmonic nanoscatters efficiently harvest the complement spectrum
components for charge generation. The present approach combines the
capacities of nanoscale color sorting and photoelectric converting
at a negligible cost of efficiency, thus providing a broad flexibility
of being utilized in various optoelectronic applications including
self-powered display, filter-free imaging, and colorful photovoltaics