scholarly journals Tuning of Fiber Optic Surface Reflectivity through Graphene Oxide-Based Layer-by-Layer Film Coatings

Photonics ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Catarina S. Monteiro ◽  
Maria Raposo ◽  
Paulo A. Ribeiro ◽  
Susana O. Silva ◽  
Orlando Frazão
Keyword(s):  
Graphene Oxide ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Growth Kinetics ◽  
Fiber Optic ◽  
Hollow Microsphere ◽  
Layer Growth ◽  
Layer By Layer ◽  
Film Coatings ◽  
Surface Reflectivity

The use of graphene oxide-based coatings on optical fibers are investigated, aiming to tune the reflectivity of optical fiber surfaces for use in precision sensing devices. Graphene oxide (GO) layers are successfully deposited onto optical fiber ends, either in cleaved or hollow microspheres, by mounting combined bilayers of polyethylenimine (PEI) and GO layers using the Layer-by-Layer (LbL) technique. The reflectivity of optical fibers coated with graphene oxide layers is investigated for the telecom region allowing to both monitor layer growth kinetics and cavity characterization. Tunable reflective surfaces are successfully attained in both cleaved optical fibers and hollow microsphere fiber-based sensors by simply coating them with PEI/GO layers through the LbL film technique.

scholarly journals Thermally Stimulated Desorption Optical Fiber-Based Interrogation System: An Analysis of Graphene Oxide Layers’ Stability

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 70
Author(s):  
Maria Raposo ◽  
Carlota Xavier ◽  
Catarina Monteiro ◽  
Susana Silva ◽  
Orlando Frazão ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Layer By Layer ◽  
Film Stability ◽  
A Value ◽  
Device Reliability ◽  
Sensor Devices ◽  
Lbl Films ◽  
The Stability

Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.

Automated Fiber-Optic System for Monitoring the Stability of the Pit Quarry Mass and Dumps

2021 ◽  
pp. 19-26
Author(s):  
А.D. Меkhtiyev ◽  
◽  
E.G. Neshina ◽  
P.Sh. Madi ◽  
D.A. Gorokhov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Light Wave ◽  
Single Mode ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Laboratory Sample ◽  
Single Mode Optical Fiber

This article ls with the issues related to the development of a system for monitoring the deformation and displacement of the rock mass leading to the collapse of the quarry sides. Monitoring system uses point-to-point fiber-optic sensors. Fiber-optic sensors and control cables of the communication line are made based on the single mode optical fibers, which allows to measure with high accuracy the deformations and displacements of the rock mass at a distance of 30-50 km. To create fiber-optic pressure sensors, an optical fiber of the ITU-T G. 652.D standard is used. Laboratory sample is developed concerning the point fiber-optic sensor made based on the two-arm Mach-Zender interferometer using a single mode optical fiber for monitoring strain (displacements) with a change in the sensitivity and a reduced influence of temperature interference leading to zero drift. The article presents a mathematical apparatus for calculating the intensity of radiation of a light wave passing through an optical fiber with and without mechanical stress. A laboratory sample of single mode optical fibers based on the Mach-Zender interferometer showed a fairly high linearity and accuracy in the measurement and can be used to control the strain of the mass after appropriate refinement of its design. Mathematical expressions are also given for determining the intensity of the light wave when the distance between the fixing points of a single mode optical fiber changes depending on the change in the external temperature. A diagram for measuring strain using a point fiber-optic strain sensor is developed. Hardware and software package is developed, which can be used to perform a number of settings of measuring channels. The work is aimed at solving the production problems of the Kenzhem quarry of AK Altynalmas JSC.

Imaging Spectroscopy Using Fiber Optics

1997 ◽  
Vol 3 (S2) ◽  
pp. 845-846
Author(s):  
S. Michael Angel ◽  
H. Trey Skinner ◽  
Brian J. Marquardt
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Imaging System ◽  
Single Point ◽  
Imaging Spectroscopy ◽  
Small Diameter ◽  
Imaging Spectrometer ◽  
Remote Spectroscopy

Optical fiber probes are routinely used with optical spectrometers to allow measurements to be made on remotely located samples. In most of these systems, however, the optical fibers are used as non-imaging “light pipes” for the transmission of laser light, and luminescence or Raman signals to and from the sample. Thus, while these systems are suitable for remote spectroscopy, they are limited to single-point measurements. In a recent paper, we showed that a small-diameter (i.e., 350 μm) coherent optical fiber bundle can be combined with an AOTF-based imaging spectrometer for fluorescence and Raman spectral micro-imaging with increased flexibility in terms of sample positioning and in-situ capabilities. The previous paper described the operation of the fiber-optic microimaging probe and AOTF imaging system and showed preliminary Raman and fluorescence images for model compounds with 4 μm resolution. We have extended this work to include a discussion of the lateral and vertical spatial resolution of the fiber-optic microprobe in a non-contact proximity-focused configuration.

Integrated Fiber Optic Sensors For Nondestructive Characterization Of Concrete Structures

1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Optical Fiber Sensor ◽  
Fiber Optic Sensors ◽  
Fiber Sensors ◽  
Fully Integrated ◽  
Integrated Optical ◽  
Concrete Elements

ABSTRACTIt is possible to monitor the initiation and progress of various mechanical or environmentally induced perturbations in concrete elements by way of fully integrated optical fiber sensors. Geometric adaptability and ease by which optical fibers can be embedded within concrete elements has led to the development of a number of innovative applications for concrete elements. This article is intended for a brief introduction into the theories, principles, and applications of fiber optic sensors as they pertain to applications in concrete.. However, due to the fact that the transduction mechanism in optical fibers is invariant of the materials employed, the principles introduced here also correspond to other structural materials. The only application related differences among various materials pertain to sensitivity and choice of optical fiber sensor types.

Applications of Active Thin Film Coatings on Optical Fibers

1996 ◽  
Vol 459 ◽  
Author(s):  
G. R. Fox ◽  
C.A.P. Muller ◽  
C. R. Wüthrich ◽  
A. L. Kholkin ◽  
N. Setter ◽  
...  
Keyword(s):  
Thin Film ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Phase Shifters ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Fiber Coating ◽  
Wavelength Tunable ◽  
Fiber Devices ◽  
Recent Developments

ABSTRACTActive thin film coatings on optical fibers provide a variety of functions that are being used to develop active all-fiber optical devices. Two types of active coatings that are of interest for device development include resistive and piezoelectric coatings. Resistive coatings can be used to heat an optical fiber, while piezoelectric coatings can be used to strain the fiber. Localized changes in the fiber waveguiding properties can be achieved by electrically activating the fiber coating. These coated fibers show promise for applications such as optical phase shifters and modulators.Recent developments in the fabrication of diffraction gratings within the core of an optical fiber have provided the means for making a variety of intra-core reflection and band pass filters. By combining these passive intra-core fiber devices with active coatings, wavelength tunable devices have been demonstrated. Wavelength tunable devices are expected to have a variety of applications in telecommunications and sensing networks. A review of recent developments in fiber coating and analysis techniques, device fabrication, and applications of active all-fiber devices are presented along with a discussion of which coating materials are of interest in active devices.

scholarly journals Curvature Analysis in Fiber Optic Cables as a Tilt Sensor Based on Macro Bending

2020 ◽  
Vol 2 (2) ◽  
pp. 91-99
Author(s):  
Imam Mulyanto
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Single Mode ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Curvature Analysis ◽  
Bending Process ◽  
Tilt Sensor

The test has been successfully carried out on optical fibers to be used as a macrobending tilt sensor using SMF-28 single mode optical fiber. The optical fiber was molded with silicon rubber, then connected to a laser light and a power meter to see the intensity of the laser power produced. The principle is carried out using the macro bending phenomenon on single mode optical fibers, where the laser light intensity in the fiber optic cable will decrease if there is a bend or bending in the fiber optic cable. We can observe the power loss resulting from the macro bending process to find out how sensitive the optical fiber is to changes in a given angle. The resulting optical fiber sensitivity value is -0.1534o/dBm.

Evanescent Wave Absorption Spectroscopy by Means of Bi-Tapered Multimode Optical Fibers

1998 ◽  
Vol 52 (4) ◽  
pp. 546-551 ◽  
Author(s):  
Anna Grazia Mignani ◽  
Riccardo Falciai ◽  
Leonardo Ciaccheri
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Absorption Spectroscopy ◽  
Evanescent Wave ◽  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Experimental Results ◽  
Multimode Optical Fiber ◽  
Wave Absorption ◽  
Reproducible Technique

This paper discusses the theoretical and experimental implications of tapering a multimode optical fiber with a view to its use in evanescent wave absorption spectroscopy. Good experimental results are obtained, showing the possibility of quadruplicating the absorbance efficiency. This easy and reproducible technique for taper fabrication is suitable for the implementation of both probes for spectroscopy and chemically assisted fiber-optic sensors.

scholarly journals Evaluation of the Detection Efficiency of LYSO Scintillator in the Fiber-Optic Radiation Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chan Hee Park ◽  
Arim Lee ◽  
Rinah Kim ◽  
Joo Hyun Moon
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Detection Efficiency ◽  
Radiation Detection ◽  
Refraction Index ◽  
Fiber Optic Sensor ◽  
Optic Radiation ◽  
Spent Fuel ◽  
Radiation Sensor

The aim of this study was to develop and evaluate fiber-optic sensors for the remote detection of gamma rays in areas that are difficult to access, such as a spent fuel pool. The fiber-optic sensor consists of a light-generating probe, such as scintillators for radiation detection, plastic optical fibers, and light-measuring devices, such as PMT. The (Lu,Y)2SiO5:Ce(LYSO:Ce) scintillator was chosen as the light-generating probe. The (Lu,Y)2SiO5:Ce(LYSO:Ce) scintillator has higher scintillation efficiency than the others and transmits light well through an optical fiber because its refraction index is similar to the refractive index of the optical fiber. The fiber-optic radiation sensor using the (Lu,Y)2SiO5:Ce(LYSO:Ce) scintillator was evaluated in terms of the detection efficiency and reproducibility for examining its applicability as a radiation sensor.

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