scholarly journals Optical Strain Measurement with Step-Index Polymer Optical Fiber Based on the Phase Measurement of an Intensity-Modulated Signal

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2319 ◽  
Author(s):  
Thomas Becker ◽  
Olaf Ziemann ◽  
Rainer Engelbrecht ◽  
Bernhard Schmauss
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Phase Measurement ◽  
Polymer Optical Fiber ◽  
Step Index ◽  
Intensity Modulated ◽  
Optical Strain ◽  
The Impact ◽  
Multi Mode

Polymer optical fibers (POFs) have been proposed for optical strain sensors due to their large elastic strain range compared to glass optical fibers (GOFs). The phase response of a single-mode polymer optical fiber (SM-POF) is well-known in the literature, and depends on the physical deformation of the fiber as well as the impact on the refractive index of the core. In this paper, we investigate the impact of strain on a step-index polymer optical fiber (SI-POF). In particular, we discuss the responsivity of an optical strain sensor which is based on the phase measurement of an intensity-modulated signal. In comparison to the phase response of an SM-POF, we must take additional influences into account. Firstly, the SI-POF is a multi-mode fiber (MMF). Consequently, we not only consider the strain dependence of the refractive index, but also its dependency on the propagation angle θz. Second, we investigate the phase of an intensity-modulated signal. The development of this modulation phase along the fiber is influenced by modal dispersion, scattering, and attenuation. The modulation phase therefore has no linear dependency on the length of the fiber, even in the unstrained state. For the proper consideration of these effects, we rely on a novel model for step-index multi-mode fibers (SI-MMFs). We expand the model to consider the strain-induced effects, simulate the strain responsivity of the sensor, and compare it to experimental results. This led to the conclusion that the scattering behavior of a SI-POF is strain-dependent, which was further proven by measuring the far field at the end of a SI-POF under different strain conditions.

scholarly journals Novel Model for the Angle and Skewness Dependent Transmission Behavior of Step-Index Polymer Optical Fiber

Fibers ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 65 ◽  
Author(s):  
Thomas Becker ◽  
Rainer Engelbrecht ◽  
Bernhard Schmauss
Keyword(s):  
Measurement Error ◽  
Optical Fibers ◽  
Optical Transmission ◽  
Real Data ◽  
Transmission System ◽  
Phase Response ◽  
Polymer Optical Fiber ◽  
Step Index ◽  
The Impact ◽  
Novel Model

Step-index polymer optical fibers (SI-POFs) are deployed in both sensing and data transmission systems. The optical transmission behavior of these fibers is complex and affected by intrinsic influences like modal dispersion, scattering and attenuation as well as extrinsic influences like the launching condition and the angular sensitivity of the receiver. Since a proper modeling of the transmission behavior is important in order to evaluate the suitability of the fiber for a specific application, we present a novel model for step-index multi-mode fibers (SI-MMFs) which considers all the previously mentioned impacts. Furthermore, the model differentiates scattering and attenuation for propagating rays not only by their propagating angle θ z but also by the skewness θ ϕ . It is therefore possible to distinguish between guided, tunneling and refracted modes. The model uses scatter and attenuation data from previously published measurements of an SI-POF and computes the impulse response of the transmission system which is transferred to the frequency domain to derive the amplitude and phase response. A possible application for SI-POF is the length or strain measurement of the fiber by measuring the phase of a harmonically modulated signal. These sensors rely on a linear relation between the length of the fiber and the phase of the modulated signal. We demonstrate the application of the model by simulating the length measurement error that occurs for these sensors by obtaining the phase response for the corresponding optical transmission system. Furthermore, we will demonstrate the flexibility of the model by varying several influences including the excitation of different mode categories and evaluate the impact on the measurement error. Finally, we compare the simulated length error derived from the model to real data obtained from a cutback measurement. An implementation of the model, which was used for all simulations in this paper, is publicly available.

scholarly journals Reflective Properties of a Polymer Micro-Transducer for an Optical Fiber Refractive Index Sensor

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6964
Author(s):  
Paweł Marć ◽  
Monika Żuchowska ◽  
Leszek R. Jaroszewicz
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Type ◽  
Optical Fiber Sensor ◽  
Refractive Index Sensor ◽  
Light Sources ◽  
New Class ◽  
Multi Mode ◽  
Selection Of

A polymer microtip manufactured at the end of a multi-mode optical fiber by using the photopolymerization process offers good reflective properties, therefore, it is applicable as an optical fiber sensor micro-transducer. The reflective properties of this microelement depend on the monomer mixture used, optical fiber type, and light source initiating polymerization. Experimental results have shown that a proper selection of these parameters has allowed the design of a new class of sensing structure which is sensitive to the refractive index (RI) changes of a liquid medium surrounding the microtip. An optical backscatter reflectometer was applied to test a group of micro-transducers. They were manufactured from two monomer mixtures on three different types of multi-mode optical fibers. They were polymerized by means of three optical light sources. Selected micro-transducers with optimal geometries were immersed in reference liquids with a known RI within the range of 1.3–1.7. For a few sensors, the linear dependences of return loss and RI have been found. The highest sensitivity was of around 208 dB/RIU with dynamic 32 dB within the range of 1.35–1.48. Sensing characteristics have minima close to RI of a polymer microelement, therefore, changing its RI can give the possibility to tune sensing properties of this type of sensor.

scholarly journals Damage detection in laminar thermoplastic composite materials by means of embedded optical fibers

2006 ◽  
Vol 60 (7-8) ◽  
pp. 176-179
Author(s):  
Aleksandar Kojovic ◽  
Irena Zivkovic ◽  
Ljiljana Brajovic ◽  
Dragan Mitrakovic ◽  
Radoslav Aleksic
Keyword(s):  
Composite Materials ◽  
Optical Fiber ◽  
Real Time ◽  
Optical Fibers ◽  
Impact Damage ◽  
Experimental Testing ◽  
Low Energy ◽  
Thermoplastic Composite ◽  
Woven Fabric ◽  
The Impact

This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide)) woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral)) as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers). Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED) was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material) could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before and after the impact, as the measure of damage. This method could be used to monitor the damage in real time, giving warnings before fatal damage occurs.

Amplified spontaneous emission of Eu(DBM)3Phen doped step-index polymer optical fiber by end-pumping with a YAG

2005 ◽  
Vol 98 (2) ◽  
pp. 912-916 ◽  
Author(s):  
Hao Liang ◽  
Biao Chen ◽  
Qijin Zhang ◽  
Zhiqiang Zheng ◽  
Hai Ming ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Spontaneous Emission ◽  
Amplified Spontaneous Emission ◽  
Polymer Optical Fiber ◽  
Step Index

Flexible porphyrin doped polymer optical fibers for rapid and remote detection of trace DNT vapor

The Analyst ◽  
2020 ◽  
Vol 145 (15) ◽  
pp. 5307-5313
Author(s):  
Huan Lin ◽  
Xin Cheng ◽  
Ming-Jie Yin ◽  
Zhouzhou Bao ◽  
Xunbin Wei ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Remote Detection ◽  
Polymer Optical Fiber ◽  
Highly Sensitive ◽  
Polymer Optical Fibers ◽  
Doped Polymer

A flexible porphyrin doped polymer optical fiber was developed for fast and highly sensitive monitoring of DNT vapors.

scholarly journals A Media Converter Prototype for 10-Mb/s Ethernet Transmission Over 425 m of Large-Core Step-Index Polymer Optical Fiber

2006 ◽  
Vol 24 (12) ◽  
pp. 4946-4952 ◽  
Author(s):  
Daniel Cardenas ◽  
Antonino Nespola ◽  
Pietro Spalla ◽  
Silvio Abrate ◽  
Roberto Gaudino
Keyword(s):  
Optical Fiber ◽  
Large Core ◽  
Polymer Optical Fiber ◽  
Step Index

scholarly journals Vortex Polymer Optical Fiber with 64 Stable OAM States

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2776
Author(s):  
José A. Borda-Hernández ◽  
Claudia M. Serpa-Imbett ◽  
Hugo E. Hernandez Figueroa
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Communication Systems ◽  
Low Cost ◽  
Higher Order ◽  
Coupling Coefficients ◽  
Polymer Optical Fiber ◽  
Optical Polymer ◽  
Polymer Optical Fibers ◽  
Low Dispersion

This research introduces a numerical design of an air-core vortex polymer optical fiber in cyclic transparent optical polymer (CYTOP) that propagates 32 orbital angular momentum (OAM) modes, i.e., it may support up to 64 stable OAM-states considering left- and right-handed circular polarizations. This fiber seeks to be an alternative to increase the capacity of short-range optical communication systems multiplexed by modes, in agreement with the high demand of low-cost, insensitive-to-bending and easy-to-handle fibers similar to others optical fibers fabricated in polymers. This novel fiber possesses unique characteristics: a diameter of 50 µm that would allow a high mechanical compatibility with commercially available polymer optical fibers, a difference of effective index between neighbor OAM modes of around 10−4 over a bandwidth from 1 to 1.6 µm, propagation losses of approximately 15 × 10−3 dB/m for all OAM modes, and a very low dispersion for OAM higher order modes (±l = 16) of up to +2.5 ps/km-nm compared with OAM lower order modes at a telecom wavelength of 1.3 µm, in which the CYTOP exhibits a minimal attenuation. The spectra of mutual coupling coefficients between modes are computed considering small bends of up to 3 cm of radius and slight ellipticity in the ring of up to 5%. Results show lower-charge weights for higher order OAM modes.

scholarly journals E-Knitted Textile with Polymer Optical Fibers for Friction and Pressure Monitoring in Socks

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 3011 ◽  
Author(s):  
Claire Guignier ◽  
Brigitte Camillieri ◽  
Michel Schmid ◽  
René M. Rossi ◽  
Marie-Ange Bueno
Keyword(s):  
Mechanical Properties ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Knitted Fabric ◽  
Bending Rigidity ◽  
Pressure Monitoring ◽  
Polymer Optical Fiber ◽  
Bending Radius ◽  
Polymer Optical Fibers ◽  
Knitted Structure

The objective of this paper is to study the ability of polymer optical fiber (POF) to be inserted in a knitted fabric and to measure both pressure and friction when walking. Firstly, POF, marketed and in development, have been compared in terms of the required mechanical properties for the insertion of the fiber directly into a knitted fabric on an industrial scale, i.e. elongation, bending rigidity, and minimum bending radius before plastic deformation. Secondly, the chosen optical fiber was inserted inside several types of knitted fabric and was shown to be sensitive to friction and compression. The knitted structure with the highest sensitivity has been chosen for sock prototype manufacturing. Finally, a feasibility study with an instrumented sock showed that it is possible to detect the different phases of walking in terms of compression and friction.

Four-wave mixing in non-step-index optical fibers: a sensitive technique for measurement of refractive-index profiles

1997 ◽  
Vol 22 (17) ◽  
pp. 1311 ◽  
Author(s):  
A. Sharma ◽  
R. Posey ◽  
L. Phillips ◽  
T. George ◽  
P. Ruffin
Keyword(s):  
Refractive Index ◽  
Optical Fibers ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Sensitive Technique ◽  
Step Index

scholarly journals Effect of glow discharge plasma on step index polymer optical fiber parameters

2016 ◽  
Vol 40 ◽  
pp. 287-296
Author(s):  
Mohamed MEDHAT ◽  
El-Sayed EL-ZAIAT ◽  
Mohamed SAUDY ◽  
Mona OMAR ◽  
Hassanein SHABAN
Keyword(s):  
Glow Discharge ◽  
Optical Fiber ◽  
Discharge Plasma ◽  
Glow Discharge Plasma ◽  
Polymer Optical Fiber ◽  
Step Index
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