scholarly journals Asymmetric Concentric Microring Resonator Label-Free Biosensors

Photonics ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Pedro Chamorro-Posada
Keyword(s):  
Silicon Nitride ◽  
Performance Improvement ◽  
Microring Resonator ◽  
The Other ◽  
Microring Resonators ◽  
Label Free ◽  
High Radiation ◽  
Radiation Losses ◽  
Single Ring ◽  
Optimized Geometries

A study of label-free silicon nitride asymmetric double-microring resonators is presented. The use of highly accurate 3D vector modal techniques permits an extensive exploration of the parameter space defining the architecture of the proposed device in the search for optimal geometries and reaching configurations not addressed in previous studies that had been limited to symmetrical configurations. Asymmetry, on the other hand, permits to access resonances that exploit the radiation-quenching properties of the structure in an optimal way. The analysis presented also includes the effect of absorption in the sensor aqueous cladding that is generally omitted. The results of the numerical survey indicate that the optimized geometries bring about a substantive performance improvement at small microring radii that are impractical for more conventional single-ring geometries due to the high radiation losses. Therefore, lower footprint devices, and a larger scale of integration, can be attained with the proposed structure.

scholarly journals High-Q-Factor Tunable Silica-Based Microring Resonators

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 256
Author(s):  
Yue-Xin Yin ◽  
Xiao-Pei Zhang ◽  
Xiao-Jie Yin ◽  
Yue Li ◽  
Xin-Ru Xu ◽  
...  
Keyword(s):  
Optical Communications ◽  
Microring Resonator ◽  
Microring Resonators ◽  
Q Factor ◽  
Notch Depth ◽  
Critical Coupling ◽  
Practical Application ◽  
Coupling Condition ◽  
High Q ◽  
Racetrack Resonator

A high-Q-factor tunable silica-based microring resonator (MRR) is demonstrated. To meet the critical-coupling condition, a Mach–Zehnder interferometer (MZI) as the tunable coupler was integrated with a racetrack resonator. Then, 40 mW electronic power was applied on the microheater on the arm of MZI, and a maximal notch depth of about 13.84 dB and a loaded Q factor of 4.47 × 106 were obtained. The proposed MRR shows great potential in practical application for optical communications and integrated optics.

scholarly journals Lean Six Sigma in Africa: Fad or real solution of competitiveness?

2013 ◽  
Vol 6 (3) ◽  
pp. 861-866 ◽  
Author(s):  
Said El Mezouari ◽  
Zahira Bouaouda ◽  
Hicham Drissi
Keyword(s):  
Performance Improvement ◽  
Continuous Improvement ◽  
Six Sigma ◽  
Lean Six Sigma ◽  
Business Development ◽  
The Other ◽  
Real Solution ◽  
Management Instrument ◽  
To Come ◽  
The Right

Companies tend increasingly to turn to the so-called continuous improvement in order to improve their performance and thus enhance their competitiveness approaches. In times of crisis, the use of these approaches becomes mandatory. In this context, the Lean Six Sigma is incontestably today a vehicle for business development as it allows performance improvement through various appropriate tools on one side, and incitement to contribution of different actors in the company, on the other side. In Africa, the Lean Six Sigma looks like an opportunity that seems to come at the right time in an environment that seems to need it. Is it then a management instrument emerging from a fad phenomena, or is it a real tool for performance improving for African companies, responding to a real need?

scholarly journals On the possible ellipticity of Saturn's ring

1924 ◽  
Vol 106 (739) ◽  
pp. 526-552 ◽  
Keyword(s):  
Nineteenth Century ◽  
The Other ◽  
Gravitational Attraction ◽  
History Of Astronomy ◽  
Small Oscillations ◽  
First Approximation ◽  
Elliptical Ring ◽  
Single Ring ◽  
History Of ◽  
Concentric Circles

Clerk Maxwell’s investigation into the constitution and stability of Saturn’s Ring was based upon the fundamental supposition that the rings were composed of particles arranged in concentric circles. Although the particles could perform small oscillations about their mean positions, it is evident that the outline of the ring would be to all appearances circular. A line in Clerke’s ‘Popular History of Astronomy in the Nineteenth Century’ (page 299) suggests that some observers have regarded the outline of the ring as elliptical. It is therefore of interest to enquire under what conditions an elliptical ring could exist. The ellipse is a more general form than a circle. If, therefore, it can be shown that an elliptic ring is possible, any explanation of the origin of the rings must take account of this fact. In this paper a single ring of particles is examined. The actual Ring of Saturn probably consists of numerous rings, one within the other. By their gravitational attraction, each will affect the motions of the others. As a first approximation, however, it is sufficient to consider the case of a single ring.

High temperature / radiation hardened capable ARM® Cortex®-M0 microcontrollers

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000046-000050
Author(s):  
R. Bannatyne ◽  
D. Gifford ◽  
K. Klein ◽  
C. Merritt
Keyword(s):  
High Temperature ◽  
Lower Cost ◽  
Cmos Technology ◽  
The Other ◽  
Device Performance ◽  
High Radiation ◽  
Plastic Package ◽  
Radiation Hardened ◽  
Temperature Radiation ◽  
On Chip

Abstract VORAGO Technologies has developed a pair of ARM Cortex M0 MCUs designed from the ground up to be high temperature capable. One of these devices is specifically developed for high temperature applications, the other adds capabilities that make it suitable for use in high radiation environments as well. These devices are fabricated using a modified version of commercial bulk 130nm CMOS technology utilizing our HARDSIL® technology, which provides immunity to the increased effects of latchup and EOS encountered at higher application temperatures. In addition to the processor these devices include features more typical of low temperature SoCs including on-chip memory, timers, and communications peripherals. In addition to the ceramic package and die format typically utilized at high temperature, a new lower-cost plastic package is available that has been characterized at higher temperatures. These devices have been characterized at temperatures up to 200C and results showing the latchup behavior and device performance are provided. Some of the tradeoffs involved in creating such devices are discussed, as well as some of the similarities and tradeoffs in creating a radiation hardened devices vs. a high temperature device.

Sensitive label-free and compact biosensor based on concentric silicon-on-insulator microring resonators

2009 ◽  
Vol 48 (25) ◽  
pp. F90 ◽  
Author(s):  
Xiaohui Li ◽  
Ziyang Zhang ◽  
Shenying Qin ◽  
Tao Wang ◽  
Fangfei Liu ◽  
...  
Keyword(s):  
Silicon On Insulator ◽  
Microring Resonators ◽  
Label Free

Microstructure and Properties of Al-Cu-Mn Alloy with Y, Zr and (Y+Zr)

2017 ◽  
Vol 898 ◽  
pp. 334-344
Author(s):  
Ting Biao Guo ◽  
Feng Zhang ◽  
Qi Li ◽  
Chen Wang ◽  
Wan Wu Ding
Keyword(s):  
Tensile Strength ◽  
Performance Improvement ◽  
Great Influence ◽  
The Other ◽  
Refined Grains ◽  
Microstructure And Properties ◽  
Comprehensive Properties ◽  
Important Significance ◽  
Better Than ◽  
Strengthening Method

As an important strengthening method, micro alloying has been widely used to improve the comprehensive properties of aluminum alloy. The research on microstructures and properties of Al-Cu-Mn alloy with Y, Zr and (Y, Zr) was conducted through OM, SEM and EDS methods. Three addition methods were comprehensively compared and the important significance of elements and relevant precipitates distribution to performance improvement was explored. The results show that adding different contents of Y, Zr and (Y, Zr) has great influence on microstructure and properties of Al-Cu-Mn alloy. Fluidity of the (Y+Zr)-containing alloy was significantly higher than that of the Zr or Y-containing one. The hardness and elongation of the Zr-containing alloy were also better than the other two groups, while with the increase of addition amounts from 0 to 0.2 %, it showed a decreasing trend. When the content was 0.3%, the grains of the Y and (Y+Zr)-containing alloys were well refined and the tensile strength and hardness increased as well, and Y-containing alloy presented the best tensile strength. After T6 heat treatment, the mechanical properties of the Y and (Zr+Y)-containing alloys were enhanced due to the dispersed θ phase and completely refined grains. And both ductile fracture ratios increased. When the content was more than 0.3%, the reticular θ phase formed that was extremely unfavorable to properties of the studied alloy. It appears that the addition of Y and Zr has an important influence on improving the properties of the Al-Cu-Mn alloy. And Y, Zr and (Y+Zr) dosages should be adjusted reasonably in the range of 0.1-0.3% to optimize and improve the alloy performance.

Soliton Pulse Generation for WDM-Based Free Space Optics Communication Using Microring Resonators

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Shahidinejad
Keyword(s):  
Free Space ◽  
Kerr Effect ◽  
Pulse Generation ◽  
Microring Resonator ◽  
Free Space Optics ◽  
Microring Resonators ◽  
Space Optics ◽  
Soliton Pulse ◽  
Chaotic Signals ◽  
Nonlinear Kerr Effect

AbstractA microring resonator (MRR) and an add/drop devices are presented to generate picosecond solitonic pulse and signal as multichannel localized wavelengths, applicable for WDM-based free space optics (FSO) communication. A Gaussian pulse is inputted to the first ring resonator of the proposed system. Because of the nonlinear Kerr effect, chaotic signals are created. The second MRR filters the generated signals and shape solitonic pulses, where the accurate FWHM of 20 ps with intensity of 2.45 W are obtained. The add/drop device is applied for tuning the solitonic pulses. Results indicate that a range of solitonic wavelengths from 1550 nm to 1600 nm are obtained, where FSR and FWHM are 144 pm and 5 pm, respectively. Finally, performance of the proposed MRR system is evaluated in terms of bit error rate (BER) and Q factor. In the analysis, the proposed solitonic pulse is compared to conventional counterparts. Using the proposed MRR system, BER and Q factor of WDM-based FSO are considerably improved.

scholarly journals A lectin-coupled porous silicon-based biosensor: label-free optical detection of bacteria in a real-time mode

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mona Yaghoubi ◽  
Fereshteh Rahimi ◽  
Babak Negahdari ◽  
Ali Hossein Rezayan ◽  
Azizollah Shafiekhani
Keyword(s):  
Fourier Transform ◽  
Porous Silicon ◽  
Real Time ◽  
Limit Of Detection ◽  
Principal Component ◽  
The Other ◽  
Detection Methods ◽  
Carbohydrate Binding ◽  
Label Free ◽  
E Coli

Abstract Accuracy and speed of detection, along with technical and instrumental simplicity, are indispensable for the bacterial detection methods. Porous silicon (PSi) has unique optical and chemical properties which makes it a good candidate for biosensing applications. On the other hand, lectins have specific carbohydrate-binding properties and are inexpensive compared to popular antibodies. We propose a lectin-conjugated PSi-based biosensor for label-free and real-time detection of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by reflectometric interference Fourier transform spectroscopy (RIFTS). We modified meso-PSiO2 (10–40 nm pore diameter) with three lectins of ConA (Concanavalin A), WGA (Wheat Germ Agglutinin), and UEA (Ulex europaeus agglutinin) with various carbohydrate specificities, as bioreceptor. The results showed that ConA and WGA have the highest binding affinity for E. coli and S. aureus respectively and hence can effectively detect them. This was confirmed by 6.8% and 7.8% decrease in peak amplitude of fast Fourier transform (FFT) spectra (at 105 cells mL−1 concentration). A limit of detection (LOD) of about 103 cells mL−1 and a linear response range of 103 to 105 cells mL−1 were observed for both ConA-E. coli and WGA-S. aureus interaction platforms that are comparable to the other reports in the literature. Dissimilar response patterns among lectins can be attributed to the different bacterial cell wall structures. Further assessments were carried out by applying the biosensor for the detection of Klebsiella aerogenes and Bacillus subtilis bacteria. The overall obtained results reinforced the conjecture that the WGA and ConA have a stronger interaction with Gram-positive and Gram-negative bacteria, respectively. Therefore, it seems that specific lectins can be suggested for bacterial Gram-typing or even serotyping. These observations were confirmed by the principal component analysis (PCA) model.

scholarly journals Compact Inner-Wall Grating Slot Microring Resonator for Label-Free Sensing

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 5038 ◽  
Author(s):  
Hongjun Gu ◽  
He Gong ◽  
Chunxue Wang ◽  
Xiaoqiang Sun ◽  
Xibin Wang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Sodium Chloride ◽  
High Sensitivity ◽  
Microring Resonator ◽  
Silicon On Insulator ◽  
Label Free ◽  
Detection Range ◽  
Sodium Chloride Solutions ◽  
Sensing Application ◽  
Index Unit

In this paper, we present and analyze a compact inner-wall grating slot microring resonator (IG-SMRR) with the footprint of less than 13 μm × 13 μm on the silicon-on-insulator (SOI) platform for label-free sensing, which comprises a slot microring resonator (SMRR) and inner-wall grating (IG). Its detection range is significantly enhanced without the limitation of the free spectral region (FSR) owing to the combination of SMRR and IG. The IG-SMRR has an ultra-large quasi-FSR of 84.5 nm as the detection range, and enlarged factor is up to over 3 compared with the conventional SMRR. The concentration sensitivities of sodium chloride solutions and D-glucose solutions are 996.91 pm/% and 968.05 pm/%, respectively, and the corresponding refractive index (RI) sensitivities are 559.5 nm/RIU (refractive index unit) and 558.3 nm/RIU, respectively. The investigation on the combination of SMRR and IG is a valuable exploration of label-free sensing application for ultra-large detection range and ultra-high sensitivity in future.

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