Analysis of a low-cost technique for the generation of broadband spectra with adjustable spectral width in optical fibers

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.

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An Optical Fiber Chemical Sensor for the Detection of Copper(II) in Drinking Water

Sensors ◽

10.3390/s19235246 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5246 ◽

Cited By ~ 3

Author(s):

Pesavento ◽

Profumo ◽

Merli ◽

Cucca ◽

Zeni ◽

...

Keyword(s):

Drinking Water ◽

Optical Fiber ◽

Optical Fibers ◽

Chemical Sensor ◽

Low Cost ◽

Self Assembled Monolayer ◽

Ph Values ◽

Highly Sensitive ◽

Selective Sensor

Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10-6 M to 2 × 10-4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.

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Fiber Embroidery of Self-Sensing Soft Actuators

Biomimetics ◽

10.3390/biomimetics3030024 ◽

2018 ◽

Vol 3 (3) ◽

pp. 24 ◽

Cited By ~ 10

Author(s):

Steven Ceron ◽

Itai Cohen ◽

Robert Shepherd ◽

James Pikul ◽

Cindy Harnett

Keyword(s):

Optical Fibers ◽

Low Cost ◽

Three Dimensional ◽

High Strength ◽

Linear Displacement ◽

Angular Rotation ◽

Linear Elements ◽

Soft Actuators ◽

Inextensible Fibers ◽

Silicone Membranes

Natural organisms use a combination of contracting muscles and inextensible fibers to transform into controllable shapes, camouflage into their surrounding environment, and catch prey. Replicating these capabilities with engineered materials is challenging because of the difficulty in manufacturing and controlling soft material actuators with embedded fibers. In addition, while linear and bending motions are common in soft actuators, rotary motions require three-dimensional fiber wrapping or multiple bending or linear elements working in coordination that are challenging to design and fabricate. In this work, an automatic embroidery machine patterned Kevlar™ fibers and stretchable optical fibers into inflatable silicone membranes to control their inflated shape and enable sensing. This embroidery-based fabrication technique is simple, low cost, and allows for precise and custom patterning of fibers in elastomers. Using this technique, we developed inflatable elastomeric actuators embedded with a planar spiral pattern of high-strength Kevlar™ fibers that inflate into radially symmetric shapes and achieve nearly 180° angular rotation and 10 cm linear displacement.

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Fabrication of an Atomic Resolution Low Cost STM-SNOM Hybrid Probe

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2006.109 ◽

2006 ◽

Vol 6 (1) ◽

pp. 72-76

Author(s):

Ruggero Micheletto ◽

Masatoshi Yokokawa ◽

Satoshi Okazakaki ◽

Yoichi Kawakami

Keyword(s):

Optical Fiber ◽

Optical Fibers ◽

Chemical Etching ◽

Low Cost ◽

Resolving Power ◽

Atomic Resolution ◽

Hybrid Fiber ◽

Horizontal Scale ◽

Simple Method ◽

One Step

We derived a simple method to fabricate STM-SNOM hybrid probes obtained from commercial cheap communication optical fibers. The tips are fabricated by a methodology that combines two well-known techniques: the selective attack by a buffered solution and the protected layer chemical etching, in a single new one-step technique. The tailored probes are then sputtered by metal and mounted on a STM setup. The usual difficulties of integrating the optical fiber in the STM head are solved originally with a particular home made mount described in details. We will show that the resulting probes reach atomic resolution on both vertical and horizontal scale, and that the optical imaging is free of artifacts and satisfactory with a lateral resolution in the order of λ/20, as far as we know the finest resolution obtained with a system based on a hybrid fiber probe. We believe that our methodology is very interesting for its simplicity of realization and for the good resolving power in both SNOM and STM modes.

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Surface Treatments to Enhance the Sensitivity of Plastic Optical Fiber Based Accelerometers

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.297 ◽

2013 ◽

Vol 543 ◽

pp. 297-301 ◽

Cited By ~ 2

Author(s):

Alberto Vallan ◽

Sabrina Grassini ◽

Guido Perrone

Keyword(s):

Optical Fibers ◽

Light Propagation ◽

Low Cost ◽

Polymer Surface ◽

Fiber Surface ◽

Industrial Applications ◽

Propagation Loss ◽

Test Facility ◽

Cantilever Bending ◽

Physical Treatments

The paper presents an all-fiber accelerometer that uses plastic optical fibers and discusses the enhancement of its sensitivity through physical treatments on the polymer surface to modify the light propagation characteristics. Given the target of being low-cost and compact, the accelerometer exploits the variation of propagation loss induced by the deformations of a miniaturized cantilever on which the fiber is fixed. This simple setup, however, does not exhibit a sufficient sensitivity unless the fiber surface is properly treated in order to enhance the loss dependence with the cantilever bending. Two approaches are compared, namely plasma micro-and nanotexturing and laser localized ablations. Several prototypes of accelerometers have been fabricated using various types of plastic fibers and characterized using a vibration test facility. Preliminary results show that both techniques are effective and can produce similar results, although accelerometer made by laser localized ablation may be more suitable for industrial applications, like the monitoring of vibrations due to moving parts of machines.

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Smartphone-Based Optical Fiber Sensor for the Assessment of a Fed-Batch Bioreactor

Engineering Proceedings ◽

10.3390/ecsa-7-08157 ◽

2020 ◽

Vol 2 (1) ◽

pp. 26

Author(s):

Marco César Prado Soares ◽

Thiago Destri Cabral ◽

Pedro Machado Lazari ◽

Matheus dos Santos Rodrigues ◽

Gildo Santos Rodrigues ◽

...

Keyword(s):

Optical Fiber ◽

Optical Fibers ◽

Sucrose Concentration ◽

Low Cost ◽

Optical Fiber Sensor ◽

Refraction Index ◽

Fed Batch ◽

Pixel Intensity ◽

Batch Bioreactor ◽

Sensing Platform

Industry is currently in a period of great expansion, the so-called “Industry 4.0”. This period relies on the development of new sensor technologies for the generation of systems capable of collecting, distributing, and delivering information. Particularly in chemical and biochemical industries, the development of portable monitoring devices can improve many process parameters, such as safety and productivity. In this work, the design of a smartphone-based optical fiber sensing platform for the online assessment of fed-batch fermentation systems is reported. The setup is comprised of a smartphone equipped with a 3D-printed case that couples optical fibers to the phone, and of an application for collecting images from the camera and then analyzing the pixel intensity. Finally, the obtained intensities are correlated to the broth refraction index, which is function of the sucrose concentration. We calculated the sensitivity of this sensor as 85.83 RIU−1 (refractive index units), and then compared its performance to results obtained with a handheld refractometer and with Monod model predictions. It showed to be a reliable, portable, and low-cost instrument for the online monitoring of bioreactors that can be easily reproducible on-site by simply printing it.

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Refractive Index Sensor Based on Twisted Tapered Plastic Optical Fibers

Photonics ◽

10.3390/photonics6020040 ◽

2019 ◽

Vol 6 (2) ◽

pp. 40 ◽

Cited By ~ 9

Author(s):

Teng ◽

Deng ◽

Liu ◽

Yang ◽

Yuan ◽

...

Keyword(s):

Refractive Index ◽

Optical Fibers ◽

Simple Structure ◽

External Medium ◽

Low Cost ◽

The Other ◽

Refractive Index Sensor ◽

Coupling Ratio ◽

Plastic Optical Fibers ◽

Drawing Method

We proposed a refractive index (RI) sensor employing two twisted tapered plastic optical fibers (POFs). The tapered POFs were fabricated by a heating and drawing method and were twisted around each other to form a coupled structure. The sensor consisted of two input ports, a twisted region, and two output ports. The tapered POF could make the light couple from one POF to the other easily. The twisted tapered POFs could constitute a self-referencing sensor, and by monitoring the changes of the coupling ratio, the variations of the external medium RIs could be measured. The RI sensing performances for the sensors with different fiber diameters and twisted region lengths were studied. The sensitivities of 1700%/RIU and −3496%/RIU in the RI ranges of 1.37–1.41 and 1.41–1.44 were obtained, respectively. The sensor is a low-cost solution for liquid RI measurement, which has the features of simple structure and easy fabrication.

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Low-Cost Refractive Index Sensor With Optical Fibers Attached to a U-Shaped Glass Tube

IEEE Sensors Letters ◽

10.1109/lsens.2018.2853982 ◽

2018 ◽

Vol 2 (3) ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Dipankar Chetia ◽

Jayanta Madhab Gogoi ◽

Hidam Kumarjit Singh ◽

Tulshi Bezboruah

Keyword(s):

Refractive Index ◽

Optical Fibers ◽

Low Cost ◽

Glass Tube ◽

Refractive Index Sensor ◽

Shaped Glass

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D-Shaped POF Sensors for Refractive Index Sensing—The Importance of Surface Roughness

Sensors ◽

10.3390/s19112476 ◽

2019 ◽

Vol 19 (11) ◽

pp. 2476 ◽

Cited By ~ 6

Author(s):

Filipa Sequeira ◽

Nunzio Cennamo ◽

Alisa Rudnitskaya ◽

Rogério Nogueira ◽

Luigi Zeni ◽

...

Keyword(s):

Surface Roughness ◽

Refractive Index ◽

Optical Fibers ◽

Low Cost ◽

Water Quality Assessment ◽

Refractive Index Sensing ◽

Plastic Optical Fibers ◽

Index Changes ◽

Low Cost Manufacturing ◽

Scattering Losses

In this study the influence of the surface roughness on the transmission capacities of D-shaped plastic optical fibers (POFs) and sensors performance was investigated. Five D-shaped POF sensors were produced and characterized for refractive index sensing between 1.33 and 1.41. The sensors were characterized using a low-cost optical sensing system based on the variation of the transmitted light though the POF with refractive index changes (RI). Higher surface roughness increases the scattering losses through the POF and influences the sensors’ performance; therefore, a balance must be attained. Generally, the best performance was achieved when the sensing region was polished with P600 sandpaper as a final polishing step. Polishing with sandpapers of lower grit size resulted in lower scattering, higher linearity of the sensor response and generally lower performance for RI sensing. A sensor resolution of 10−3–10−4 RIU, dependent on the value of the external refractive index, was obtained through simple and low-cost manufacturing procedures. The obtained results show the importance of surface roughness in the development of POF sensors which can be used in several applications, such as for water quality assessment.

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