scholarly journals Designing Mid-Infrared Gold-Based Plasmonic Slot Waveguides for CO2-Sensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2669
Author(s):  
Parviz Saeidi ◽  
Bernhard Jakoby ◽  
Gerald Pühringer ◽  
Andreas Tortschanoff ◽  
Gerald Stocker ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Propagation Loss ◽  
Asymmetric Structure ◽  
Free Standing ◽  
Propagation Length ◽  
Mid Infrared ◽  
Sensing Applications ◽  
A Value ◽  
Standing Structure ◽  
Slot Waveguides

Plasmonic slot waveguides have attracted much attention due to the possibility of high light confinement, although they suffer from relatively high propagation loss originating from the presence of a metal. Although the tightly confined light in a small gap leads to a high confinement factor, which is crucial for sensing applications, the use of plasmonic guiding at the same time results in a low propagation length. Therefore, the consideration of a trade-off between the confinement factor and the propagation length is essential to optimize the waveguide geometries. Using silicon nitride as a platform as one of the most common material systems, we have investigated free-standing and asymmetric gold-based plasmonic slot waveguides designed for sensing applications. A new figure of merit (FOM) is introduced to optimize the waveguide geometries for a wavelength of 4.26 µm corresponding to the absorption peak of CO2, aiming at the enhancement of the confinement factor and propagation length simultaneously. For the free-standing structure, the achieved FOM is 274.6 corresponding to approximately 42% and 868 µm for confinement factor and propagation length, respectively. The FOM for the asymmetric structure shows a value of 70.1 which corresponds to 36% and 264 µm for confinement factor and propagation length, respectively.

scholarly journals Numerical analysis of an infrared gas sensor utilizing an indium-tin-oxide-based plasmonic slot waveguide

2022 ◽  
Vol 11 (1) ◽  
pp. 15-20
Author(s):  
Parviz Saeidi ◽  
Bernhard Jakoby ◽  
Gerald Pühringer ◽  
Andreas Tortschanoff ◽  
Gerald Stocker ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Noble Metals ◽  
Microelectromechanical Systems ◽  
Propagation Loss ◽  
Slot Waveguide ◽  
Plasmonic Waveguides ◽  
Propagation Length ◽  
Plasmonic Material ◽  
Sensing Applications

Abstract. Plasmonic waveguides have attracted much attention owing to the associated high field intensity at the metal–dielectric interface and their ability to confine the modes at the nanometer scale. At the same time, they suffer from relatively high propagation loss, which is due to the presence of metal. Several alternative materials have been introduced to replace noble metals, such as transparent conductive oxides (TCOs). A particularly popular TCO is indium tin oxide (ITO), which is compatible with standard microelectromechanical systems (MEMS) technology. In this work, the feasibility of ITO as an alternative plasmonic material is investigated for infrared absorption sensing applications: we numerically design and optimize an ITO-based plasmonic slot waveguide for a wavelength of 4.26 µm, which is the absorption line of CO2. Our optimization is based on a figure of merit (FOM), which is defined as the confinement factor divided by the imaginary part of the effective mode index (i.e., the intrinsic damping of the mode). The obtained optimal FOM is 3.2, which corresponds to 9 µm and 49 % for the propagation length (characterizing the intrinsic damping) and the confinement factor, respectively.

Footprint Analysis of CMOS Compatible Silicon-on-Insulator based Photonic Waveguides

2020 ◽  
Vol 12 ◽  
Author(s):  
Veer Chandra ◽  
Rakesh Ranjan
Keyword(s):  
Silicon On Insulator ◽  
Propagation Loss ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Propagation Length ◽  
Footprint Analysis ◽  
Photonic Waveguides ◽  
Cmos Compatible ◽  
The Impact ◽  
Slot Waveguides

Aim: Establish the efficient footprint size, i.e., the total substrate width of photonic waveguides (Ridge, Rib, and Slot) under the fundamental mode propagation constraints. Objective: By varying the total substrate width for all photonic waveguides (Ridge, Rib, and Slot) with respect to four major waveguide parameters, namely effective refractive index, propagation loss, propagation length, and confinement percentage, the converged values of these waveguide parameters have to be obtained. Methods: The finite element method (FEM) based simulations, using the COMSOL Multiphysics, have been used to study the modal characteristics of photonic waveguides to achieve their efficient footprint size. Results: The total substrate widths have been obtained for the all four parameters and considering the impact of all these waveguide parameters simultaneously, the efficient total substrate width have been recognized as 2500 nm, 4000 nm, and 3000 nm, respectively for Ridge, Rib, and Slot waveguides. Conclusion: The efficient waveguide footprints, i.e., the total substrate widths for the three photonic waveguides, namely Ridge, Rib and Slot waveguides have been established.

scholarly journals Free-Standing Waveguides for Sensing Applications in the Mid-Infrared

2021 ◽  
Author(s):  
Marek Vlk ◽  
Anurup Datta ◽  
Sebastian Alberti ◽  
Ganapathy Senthil Murugan ◽  
Astrid Aksnes ◽  
...  
Keyword(s):  
Free Standing ◽  
Mid Infrared ◽  
Sensing Applications

Mid-infrared silicon photonics for sensing applications

2012 ◽  
Vol 1437 ◽  
Author(s):  
Goran Z. Mashanovich ◽  
Milan M. Milosevic ◽  
Milos Nedeljkovic ◽  
David Cox ◽  
Vittorio M. N. Passaro ◽  
...  
Keyword(s):  
Wavelength Region ◽  
Medical Diagnostics ◽  
Group Iv ◽  
Propagation Loss ◽  
Ring Resonators ◽  
Optical Modulator ◽  
Active Device ◽  
Mid Infrared ◽  
Infrared Wavelength ◽  
Sensing Applications

ABSTRACTThe mid-infrared wavelength region offers a plethora of possible applications ranging from sensing, medical diagnostics and free space communications, to thermal imaging and IR countermeasures. Hence group IV mid-infrared photonics is attracting more research interest lately. Sensing is an especially attractive area as fundamental vibrations of many important gases are found in the 3 to 14 μm spectral region. To realise group IV photonic mid-infrared sensors several serious challenges need to be overcome. The first challenge is to find suitable material platforms for the mid-infrared. In this paper we present experimental results for passive mid-infrared photonic devices realised in silicon-on-insulator (SOI), silicon-on-sapphire (SOS), and silicon on porous silicon (SiPSi). Although silicon dioxide is lossy in most parts of the mid-infrared, we have shown that it has potential to be used in the 3-4 μm region. We have characterized SOI waveguides with < 1 dB/cm propagation loss. We have also designed and fabricated SOI passive devices such as MMIs and ring resonators. For longer wavelengths SOS or SiPSi structures could be used. An important active device for long wavelength group IV photonics will be an optical modulator. We present relationships for the free-carrier induced electro-refraction and electro-absorption in silicon in the mid-infrared wavelength range. Electro-absorption modulation is calculated from impurity-doping spectra taken from the literature, and a Kramers-Kronig analysis of these spectra is used to predict electro-refraction modulation. We have examined the wavelength dependence of electro-refraction and electro-absorption, and found that the predictions suggest longer-wave modulator designs will in many cases be different than those used in the telecom range.

scholarly journals Suspended Microracetrack Resonator with Lateral Sub-wavelength-Grating Metamaterial Cladding for Mid-infrared Sensing Applications

2018 ◽  
Vol 17 ◽  
pp. 02005 ◽  
Author(s):  
Zecen Zhang ◽  
Geok Ing Ng ◽  
Ting Hu ◽  
Haodong Qiu ◽  
Xin Guo ◽  
...  
Keyword(s):  
Chemical Sensing ◽  
Extinction Ratio ◽  
Silicon On Insulator ◽  
Propagation Loss ◽  
Index Method ◽  
Mid Infrared ◽  
Infrared Sensing ◽  
Sensing Applications ◽  
The One ◽  
Sub Wavelength

A one-time etching suspended microracetrack resonator with lateral sub-wavelength-grating (SWG) metamaterial cladding is theoretically and experimentally demonstrated on commercial 340 nm-thick-top-silicon silicon-on-insulator (SOI) platform for mid-infrared (MIR) bio-chemical sensing applications. The suspended structure can offer a larger exposed area of waveguides with the testing chemicals as well as a decent sensitivity. And the one-time etching process also eases the fabrication. The suspended waveguide is optimized with a balance between propagation loss and the sensitivity. The suspended microracetrack resonator is experimentally measured at 2 μm wavelength and well fitted with an extinction ratio (ER) of 12.3 dB and a full-width-at-half-maximum (FWHM) of 0.12 nm, which corresponds to a quality factor (Q factor) of 16600. With the equivalent refractive index method and a specially developed numerical model, the expected sensitivities of fundamental TE and TM mode were calculated as 58 nm/RIU and 303 nm/RIU respectively. This one-time etching suspended microracetrack resonator shows great potential in MIR optical bio-chemical sensing applications.

Effects of Nb doping on thermoelectric properties of Zn4Sb3 at high temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 430-435 ◽  
Author(s):  
D. Li ◽  
H.H. Hng ◽  
J. Ma ◽  
X.Y. Qin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Performance ◽  
Temperature Range ◽  
A Value ◽  
Nb Doping ◽  
Thermal Conductivities

The thermoelectric properties of Nb-doped Zn4Sb3 compounds, (Zn1–xNbx)4Sb3 (x = 0, 0.005, and 0.01), were investigated at temperatures ranging from 300 to 685 K. The results showed that by substituting Zn with Nb, the thermal conductivities of all the Nb-doped compounds were lower than that of the pristine β-Zn4Sb3. Among the compounds studied, the lightly substituted (Zn0.995Nb0.005)4Sb3 compound exhibited the best thermoelectric performance due to the improvement in both its electrical resistivity and thermal conductivity. Its figure of merit, ZT, was greater than the undoped Zn4Sb3 compound for the temperature range investigated. In particular, the ZT of (Zn0.995Nb0.005)4Sb3 reached a value of 1.1 at 680 K, which was 69% greater than that of the undoped Zn4Sb3 obtained in this study.

The Influence of Silicon Dopant and Processing on Thermoelectric Properties of B4C Ceramics

1998 ◽  
Vol 545 ◽  
Author(s):  
Ke-Feng Cai ◽  
Ce-Wen Nan ◽  
Xin-Min Min
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
A Value ◽  
Si Doped

AbstractB4C ceramics doped with various content of Si (0 to 2.03 at%) are prepared via hot pressing. The composition and microstructure of the ceramics are characterized by means of XRD and EPMA. Their electrical conductivity and Seebeck coefficient of the samples are measured from room temperature up to 1500K. The electrical conductivity increases with temperature, and more rapidly after 1300K; the Seebeck coefficient of the ceramics also increases with temperature and rises to a value of about 320μVK−1. The value of the figure of merit of Si-doped B4C rises to about 4 × 10−4K−1 at 1500K.

A Novel Micromechanical Resonator Using Two-Dimensional Phononic Crystal Slab

2011 ◽  
Vol 254 ◽  
pp. 195-198
Author(s):  
Nan Wang ◽  
Fu Li Hsiao ◽  
Moorthi Palaniapan ◽  
Ming Lin Julius Tsai ◽  
Jeffrey B.W. Soon ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Acoustic Resonance ◽  
Two Dimensional ◽  
Free Standing ◽  
Sensing Applications ◽  
Aln Film ◽  
Digital Transducers ◽  
Square Array ◽  
Quality Factor Q

Two-dimensional (2-D) Silicon phononic crystal (PnC) slab of a square array of cylindrical air holes in a 10μm thick free-standing silicon plate with line defects is characterized as a cavity-mode PnC resonator. Piezoelectric aluminum nitride (AlN) film is deployed as the inter-digital transducers (IDT) to transmit and detect acoustic waves, thus making the whole microfabrication process CMOS-compatible. Both the band structure of the PnC and the transmission spectrum of the proposed PnC resonator are analyzed and optimized using finite element method (FEM). The measured quality factor (Q factor) of the microfabricated PnC resonator is over 1,000 at its resonant frequency of 152.46MHz. The proposed PnC resonator shows promising acoustic resonance characteristics for RF communications and sensing applications.

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