313 research outputs found
Simulation of Plasmonic Waveguides Based on Long-Range Surface Plasmon Polaritons
The demand for faster and smaller computing devices is growing larger and larger. In the recent decade, research has proven that plasmonic devices have exciting characteristics and performance for next generation on‑chip structures. However, most of these devices contain noble metals and are not CMOS compatible. This work numerically investigates the performance of plasmonic waveguide designs made of TiN, a CMOS compatible material with optical properties similar to gold. Through our work, we demonstrate that TiN nanophotonic devices can be useful for inter-chip connections. A series of simulations using COMSOL Multiphysics were performed to test the performance of these structures. 2D simulations were completed to gain insights into the relationship between the mode size, propagation length trade-off and how additional parameters such as cladding material, a slight mismatch in refractive index of super and substrate, and the thickness of the metal inside the waveguide, affect performance. We found that waveguides using materials of higher refractive will have better mode confinement, albeit with larger losses. If the same material is used, a slight change of refractive index typically in the range of ±0.01, causes the mode to expand to the side of lower index. Additional 3D simulations for waveguide bends, power splitters, and couplers are still in progress. The data of bend loss, power distribution, and mode shapes will be collected upon completion of the 3-D models. With the simulation data, our group will fabricate these waveguides accordingly and attempt further lab experiments to explore how these structures behave
Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications
Optical properties of colloidal plasmonic titanium nitride nanoparticles are
examined with an eye on their photothermal via transmission electron microscopy
and optical transmittance measurements. Single crystal titanium nitride cubic
nanoparticles with an average size of 50 nm exhibit plasmon resonance in the
biological transparency window. With dimensions optimized for efficient
cellular uptake, the nanoparticles demonstrate a high photothermal conversion
efficiency. A self-passivating native oxide at the surface of the nanoparticles
provides an additional degree of freedom for surface functionalization.Comment: 17 pages, 4 figures, 1 abstract figur
Plasmonic waveguides cladded by hyperbolic metamaterials
Strongly anisotropic media with hyperbolic dispersion can be used for
claddings of plasmonic waveguides. In order to analyze the fundamental
properties of such waveguides, we analytically study 1D waveguides arranged of
a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure. We show
that hyperbolic metamaterial claddings give flexibility in designing the
properties of HIH waveguides. Our comparative study on 1D plasmonic waveguides
reveals that HIH-type waveguides can have a higher performance than MIM or IMI
waveguides
Transparent conducting oxides for electro-optical plasmonic modulators
Abstract:The ongoing quest for ultra-compact optical devices has reached a bottleneck due to the diffraction limit in conventional photonics. New approaches that provide subwavelength optical elements, and therefore lead to miniaturization of the entire photonic circuit, are urgently required. Plasmonics, which combines nanoscale light confinement and optical-speed processing of signals, has the potential to enable the next generation of hybrid information-processing devices, which are superior to the current photonic dielectric components in terms of speed and compactness. New plasmonic materials (other than metals), or optical materials with metal-like behavior, have recently attracted a lot of attention due to the promise they hold to enable low-loss, tunable, CMOScompatible devices for photonic technologies. In this review, we provide a systematic overview of various compact optical modulator designs that utilize a class of the most promising new materials as the active layer or core— namely, transparent conducting oxides. Such modulators can be made low-loss, compact, and exhibit high tunability while offering low cost and compatibility with existing semiconductor technologies. A detailed analysis of different configurations and their working characteristics, such as their extinction ratio, compactness, bandwidth, and losses, is performed identifying the most promising designs.</jats:p
Temperature-dependent optical properties of plasmonic titanium nitride thin films
Due to their exceptional plasmonic properties, noble metals such as gold and
silver have been the materials of choice for the demonstration of various
plasmonic and nanophotonic phenomena. However, noble metals' softness, lack of
tailorability and low melting point along with challenges in thin film
fabrication and device integration have prevented the realization of real-life
plasmonic devices.In the recent years, titanium nitride (TiN) has emerged as a
promising plasmonic material with good metallic and refractory (high
temperature stable) properties. The refractory nature of TiN could enable
practical plasmonic devices operating at elevated temperatures for energy
conversion and harsh-environment industries such as gas and oil. Here we report
on the temperature dependent dielectric functions of TiN thin films of varying
thicknesses in the technologically relevant visible and near-infrared
wavelength range from 330 nm to 2000 nm for temperatures up to 900 0C using
in-situ high temperature ellipsometry. Our findings show that the complex
dielectric function of TiN at elevated temperatures deviates from the optical
parameters at room temperature, indicating degradation in plasmonic properties
both in the real and imaginary parts of the dielectric constant. However, quite
strikingly, the relative changes of the optical properties of TiN are
significantly smaller compared to its noble metal counterparts. Using
simulations, we demonstrate that incorporating the temperature-induced
deviations into the numerical models leads to significant differences in the
optical responses of high temperature nanophotonic systems. These studies hold
the key for accurate modeling of high temperature TiN based optical elements
and nanophotonic systems for energy conversion, harsh-environment sensors and
heat-assisted applications.Comment: 23 pages, 9 figures and 5 table
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