scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

2020 ◽  
Vol 2 (2) ◽  
pp. 91-99
Author(s):  
Imam Mulyanto

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.


2019 ◽  
Vol 9 (2) ◽  
pp. 11-15
Author(s):  
Sisca Arisya Harry Andhina

Macrobending often occurs in optical fibers that embedded in the ground due to shifting of soil or rocks in the ground causing interference in transmission. In this study used single-mode-multimode-singlemode fiber optic cable connected manually and axially measured using a light source test equipment and optical power meter and the results will be compared. The measurement results obtained the greater  value of macrobending losses with the smaller the diameter of the winding, and the greater the number of turns. The highest value of macrobending losses in multimode cables is -1.48dB at 0.5cm diameter with 5 turns, highest value of macrobending losses on single mode cables is -12.73dB at 0.5cm diameter with 5 turns,  lowest value of macrobending losses for multimode cables is -0.44dB at 5cm diameter with 1 twist, lowest macrobending losses in singlemode cables is -1.69dB at 5cm diameter with 1 twist. While the value of macrobending losses on axially connected SMS cables shows the highest value of macrobending losses on multimode cables is -1.12dB in diameter of 0.5cm with 5 turns,  highest value of macrobending losses on singlemode cables is -1.18dB at diameter of 0.5cm with 5 turns,  lowest value for macrobending losses on multimode cables is -0.66dB at 5cm in diameter with 1 twist, the smallest value for macrobending losses on singlemode cables is -0.27dB at 5cm diameter with 1 twist . The measurement results also showed that the macrobending losses of manually connected SMS cables were greater than the macrobending losses of axially connected SMS cables.


Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 107
Author(s):  
Nakash Nazeer ◽  
Xuerui Wang ◽  
Roger M. Groves

This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of each of the morphing modules. The deflection estimation is carried out by interrogating optical fibers that are bonded on to the wing’s inner surface. A novel application is demonstrated using this method that utilizes the least amount of sensors for load monitoring purposes. The fiber optic sensor data is used to measure the deflections of the modules in the wind tunnel using a multi-modal fiber optic sensing approach and is compared to the deflections estimated by the actuators. Each module is probed by single-mode optical fibers that contain just four grating sensors and consider both bending and torsional deformations. The fiber optic method in this work combines the principles of hybrid interferometry and FBG spectral sensing. The analysis involves an initial calibration procedure outside the wind tunnel followed by experimental testing in the wind tunnel. This method is shown to experimentally achieve an accuracy of 2.8 mm deflection with an error of 9%. The error sources, including actuator dynamics, random errors, and nonlinear mechanical backlash, are identified and discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aizhan Issatayeva ◽  
Aida Amantayeva ◽  
Wilfried Blanc ◽  
Daniele Tosi ◽  
Carlo Molardi

AbstractThis paper presents the performance analysis of the system for real-time reconstruction of the shape of the rigid medical needle used for minimally invasive surgeries. The system is based on four optical fibers glued along the needle at 90 degrees from each other to measure distributed strain along the needle from four different sides. The distributed measurement is achieved by the interrogator which detects the light scattered from each section of the fiber connected to it and calculates the strain exposed to the fiber from the spectral shift of that backscattered light. This working principle has a limitation of discriminating only a single fiber because of the overlap of backscattering light from several fibers. In order to use four sensing fibers, the Scattering-Level Multiplexing (SLMux) methodology is applied. SLMux is based on fibers with different scattering levels: standard single-mode fibers (SMF) and MgO-nanoparticles doped fibers with a 35–40 dB higher scattering power. Doped fibers are used as sensing fibers and SMFs are used to spatially separate one sensing fiber from another by selecting appropriate lengths of SMFs. The system with four fibers allows obtaining two pairs of opposite fibers used to reconstruct the needle shape along two perpendicular axes. The performance analysis is conducted by moving the needle tip from 0 to 1 cm by 0.1 cm to four main directions (corresponding to the locations of fibers) and to four intermediate directions (between neighboring fibers). The system accuracy for small bending (0.1–0.5 cm) is 90$$\%$$ % and for large bending (0.6–1 cm) is approximately 92$$\%$$ % .


1998 ◽  
Vol 20 (2) ◽  
pp. 103-112 ◽  
Author(s):  
H. Wen ◽  
D.G. Wiesler ◽  
A. Tveten ◽  
B. Danver ◽  
A. Dandridge

This paper presents several designs of high-sensitivity, compact fiber-optic ultrasound sensors that may be used for medical imaging applications. These sensors translate ultrasonic pulses into strains in single-mode optical fibers, which are measured with fiber-based laser interferometers at high precision. The sensors are simpler and less expensive to make than piezoelectric sensors, and are not susceptible to electromagnetic interference. It is possible to make focal sensors with these designs, and several schemes are discussed. Because of the minimum bending radius of optical fibers, the designs are suitable for single element sensors rather than for arrays.


Author(s):  
А.D. Меkhtiyev ◽  
◽  
E.G. Neshina ◽  
P.Sh. Madi ◽  
D.A. Gorokhov ◽  
...  

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.


1997 ◽  
Vol 3 (S2) ◽  
pp. 845-846
Author(s):  
S. Michael Angel ◽  
H. Trey Skinner ◽  
Brian J. Marquardt

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.


1995 ◽  
Vol 166 ◽  
pp. 362-362
Author(s):  
Peiqian Zhao ◽  
V. Coudé Du Foresto ◽  
J.-M. Mariotti ◽  
P. Lena ◽  
Bifang Zhou

Long baseline optical interferometry has been successfully employed to measure the diameters of stars. In this technique, bandwidth smearing can affect the measurement accuracy. These bandwidth smearing effects can be, to some extent, eliminated by dividing the whole observing spectral band into sub-bands and calculating the star's diameter based on the visibilities and spatial frequencies at the corresponding sub-bands. In the visible range, dividing the whole spectral band can be implemented by introducing a spectrograph, while in the IR domain, this operation can be performed efficiently with the technique of double Fourier interferometry (DFI) without losing the advantage of multiplexing. In particular, the use of IR single-mode fiber optics for DFI will make the interferometer extremely compact, light, insensitive to surrounding conditions, etc. We established an IR single-mode fiber optic double Fourier interferometer in the laboratory, in which the optical path difference modulations are generated by stretching fiber arms and the beam combination is carried out with a fiber optic directional coupler. In this paper, we report on experiments and experimental results from measurements of the diameter of an artificial star with the technique of fiber optic DFI.


1992 ◽  
Author(s):  
Vasilios E. Kalomiris ◽  
Peter A. Michaels, Jr. ◽  
Anne E. Miller ◽  
Man F. Yan

This article studies the parameters of fiber-optic communication lines (FOCL) in the temperature range. For research, a climatic unit has been developed that allows a wide temperature range for testing (from -90°C to + 90°C) and an experimental complex for investigating the stability of optical parameters of a fiber-optic cable with temperature changes in the range from + 18°C to + 76°C. A technology of sequential switching of optical fibers of a fiber-optic cable by means of welding is proposed, thanks to which the constructive problem of placing a long optical fiber in a limited volume of a heat chamber is solved. Measurement of changes in the attenuation of fiber-optic communication lines with a monotonic change in positive temperatures in the direction of increasing and decreasing temperature.


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