Modeling of ZnO nanorods for evanescent field optical sensors

2007 ◽  
Vol 204 (10) ◽  
pp. 3487-3495 ◽  
Author(s):  
Sandra Börner ◽  
Christian E. Rüter ◽  
Tobias Voss ◽  
Detlef Kip ◽  
Wolfgang Schade
Keyword(s):  
Optical Sensors ◽  
Zno Nanorods ◽  
Evanescent Field

Star cross section polymer fiber for evanescent field optical sensors

2007 ◽  
Author(s):  
E. F. Chillcce ◽  
W. M. Faustino ◽  
G. J. Jacob ◽  
E. Rodriguez ◽  
W. M. Moreira ◽  
...  
Keyword(s):  
Cross Section ◽  
Optical Sensors ◽  
Evanescent Field ◽  
Polymer Fiber

scholarly journals Diameter-optimized high-order waveguide nanorods for fluorescence enhancement applied in ultrasensitive bioassays

Nanoscale ◽  
2019 ◽  
Vol 11 (30) ◽  
pp. 14322-14329 ◽  
Author(s):  
Baosheng Du ◽  
Chengchun Tang ◽  
Dan Zhao ◽  
Hong Zhang ◽  
Dengfeng Yu ◽  
...  
Keyword(s):  
Fluorescence Enhancement ◽  
Zno Nanorods ◽  
Evanescent Field ◽  
High Order ◽  
High Fluorescence

High fluorescence enhancement has been realized by optimizing the evanescent field of ZnO nanorods.

scholarly journals Application of Polydopamine Functionalized Zinc Oxide for Glucose Biosensor Design

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2918
Author(s):  
Viktoriia Fedorenko ◽  
Daina Damberga ◽  
Karlis Grundsteins ◽  
Arunas Ramanavicius ◽  
Simonas Ramanavicius ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Sensors ◽  
Electrochemical Sensors ◽  
Zno Nanorods ◽  
Electrochemical Determination ◽  
Glucose Biosensor ◽  
Biocompatible Polymer ◽  
Optically Transparent ◽  
Optically Transparent Electrodes

Zinc oxide (ZnO) nanostructures are widely used in optical sensors and biosensors. Functionalization of these nanostructures with polymers enables optical properties of ZnO to be tailored. Polydopamine (PDA) is a highly biocompatible polymer, which can be used as a versatile coating suitable for application in sensor and biosensor design. In this research, we have grown ZnO-based nanorods on the surface of ITO-modified glass-plated optically transparent electrodes (glass/ITO). Then the deposition of the PDA polymer layer on the surface of ZnO nanorods was performed from an aqueous PDA solution in such a way glass/ITO/ZnO-PDA structure was formed. The ZnO-PDA composite was characterized by SEM, TEM, and FTIR spectroscopy. Then glucose oxidase (GOx) was immobilized using crosslinking by glutaraldehyde on the surface of the ZnO-PDA composite, and glass/ITO/ZnO-PDA/GOx-based biosensing structure was designed. This structure was applied for the photo-electrochemical determination of glucose (Glc) in aqueous solutions. Photo-electrochemical determination of glucose by cyclic voltammetry and amperometry has been performed by glass/ITO/ZnO-PDA/GOx-based biosensor. Here reported modification/functionalization of ZnO nanorods with PDA enhances the photo-electrochemical performance of ZnO nanorods, which is well suited for the design of photo-electrochemical sensors and biosensors.

scholarly journals Evanescent Field Controllable MZ Sensor via Femtosecond Laser Processing and Mechanic Polishing

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1421
Author(s):  
Zong-Da Zhang ◽  
Yan-Zhao Duan ◽  
Qi Guo ◽  
Si Gao ◽  
Bing-Rong Gao
Keyword(s):  
Refractive Index ◽  
Femtosecond Laser ◽  
Optical Sensors ◽  
Light Propagation ◽  
Bulk Material ◽  
Measurement Range ◽  
Evanescent Field ◽  
Zehnder Interferometer ◽  
On Chip ◽  
Mach Zehnder Interferometer

Recently, optical sensors interacting with evanescent fields and the external environment around waveguides have attracted extensive attention. In the process of light propagation in the waveguide, the depth of the evanescent field is closely related to the accuracy of the optical sensor, and adjusting the depth of the evanescent field to obtain higher accuracy has become the primary challenge in fabricating on-chip optical sensors. In this study, the waveguide structure of a Mach–Zehnder interferometer was written directly in Corning Eagle 2000 borosilicate glass by a femtosecond laser, and the sensing window was exposed out of the bulk material by mechanical polishing. The refractive index detection device based on the proposed on-chip Mach–Zehnder interferometer has the advantages of small volume, light weight, and good stability. Its sensitivity can reach 206 nm/RIU or 337 dB/RIU, and the theoretical maximum measurement range is 1–1.508. Therefore, it can measure the refractive index quickly and accurately in extreme or complex environments, and has excellent application prospects.

Effects of Seed Layer Coating and Oxygen Plasma Treatment on the Growth of ZnO Nanorods for UV Photodetector Applications

2020 ◽  
Vol 20 (7) ◽  
pp. 4340-4343
Author(s):  
Hyun-Jung Kim ◽  
Young-Hyuk Chung ◽  
In-Tae Hwang ◽  
Kyu-Won Jang ◽  
Hyun-Seok Kim
Keyword(s):  
Plasma Treatment ◽  
Optical Sensors ◽  
Dark Current ◽  
Seed Layer ◽  
Zno Nanorods ◽  
Oxygen Plasma Treatment ◽  
Process Conditions ◽  
Current Ratio ◽  
Recovery Times ◽  
Layer Coating

Dark current in optical sensors has been one of their issues. The performance of these sensors can be improved by reducing their dark current. In this study, we investigated UV sensors based on ZnO nanorods (ZNRs), in particular, their current–voltage characteristics, response and recovery times, on–off current ratio, and responsivity as a function of the device process conditions. The number of seed layer coatings was changed and an oxygen (O2) plasma treatment was applied to ZNRs. A microwave-assisted growth (MAG) method was used to grow ZNRs. The MAG method is one way to shorten device manufacturing time. The small number of seed layer coating processes played a role in reducing the dark current of the sensor. The O2 plasma treatment further reduced the dark current. The crystal quality of ZNRs was affected by changes in the sensor fabrication process. Although the O2 plasma treated device had an increased on–off current ratio, the response time was increased.

scholarly journals Extraordinary evanescent field confinement waveguide sensor for mid-infrared trace gas spectroscopy

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Marek Vlk ◽  
Anurup Datta ◽  
Sebastián Alberti ◽  
Henock Demessie Yallew ◽  
Vinita Mittal ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Free Space ◽  
Gas Sensing ◽  
Evanescent Field ◽  
Trace Gas ◽  
Mid Infrared ◽  
Space Optics ◽  
Sensor Performance ◽  
On Chip ◽  
Waveguide Sensor

AbstractNanophotonic waveguides are at the core of a great variety of optical sensors. These structures confine light along defined paths on photonic chips and provide light–matter interaction via an evanescent field. However, waveguides still lag behind free-space optics for sensitivity-critical applications such as trace gas detection. Short optical pathlengths, low interaction strengths, and spurious etalon fringes in spectral transmission are among the main reasons why on-chip gas sensing is still in its infancy. In this work, we report on a mid-infrared integrated waveguide sensor that successfully addresses these drawbacks. This sensor operates with a 107% evanescent field confinement factor in air, which not only matches but also outperforms free-space beams in terms of the per-length optical interaction. Furthermore, negligible facet reflections result in a flat spectral background and record-low absorbance noise that can finally compete with free-space spectroscopy. The sensor performance was validated at 2.566 μm, which showed a 7 ppm detection limit for acetylene with only a 2 cm long waveguide.

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Optical Sensors ◽  
Chemical Sensors ◽  
Transcutaneous Oxygen ◽  
Starting Values ◽  
Two Systems ◽  
Transcutaneous Oxygen Pressure ◽  
New Sensors ◽  
Changes Over Time ◽  
Over Time

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.

High-voltage monitoring by the fiber-optic recirculating measuring system

2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov
Keyword(s):  
Optical Fibers ◽  
High Voltage ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Electric Power Industry ◽  
Measuring System ◽  
Voltage Range ◽  
External Electromagnetic Fields ◽  
Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

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