Plastic Optical Fiber Research Articles

Implementasi dan Pengaruh Time Division Multiplexing (TDM) terhadap Kualitas Transmisi Sinyal

Time Division Multiplexing (TDM) is a multiplexing technique that enables the transmission of multiple signals over a single communication channel by allocating separate time slots for each signal stream. This study aims to analyze the working principles of TDM, examples of its implementation, as well as the benefits and drawbacks of TDM in communication networks. The findings show that TDM can enhance data transmission efficiency through flexible bandwidth allocation, minimizing signal interference and thereby improving signal quality. Due to these advantages, TDM is widely used in fiber optic communication systems, such as telephone and internet networks. Additionally, all data processing is conducted within integrated circuits utilizing Plastic Optical Fiber (POF), allowing TDM to be implemented at a low cost.

Optoelectronic Oscillator Using Visible LEDs and Plastic Optical Fibers

Optoelectronic Oscillator Using Visible LEDs and Plastic Optical Fibers

An MIP-Based PFAS Sensor Exploiting Nanolayers on Plastic Optical Fibers for Ultra-Wide and Ultra-Low Detection Ranges-A Case Study of PFAS Detection in River Water.

In this work, a novel optical-chemical sensor for the detection of per- and polyfluorinated substances (PFASs) in a real scenario is presented. The proposed sensing approach exploits the multimode characteristics of plastic optical fibers (POFs) to achieve unconventional sensors via surface plasmon resonance (SPR) phenomena. The sensor is realized by the coupling of an SPR-POF platform with a novel chemical chip based on different polymeric nanolayers over the core of a D-shaped POF, one made up of an optical adhesive and one of a molecularly imprinted polymer (MIP) for PFAS. The chemical chip is used to launch the light into the SPR D-shaped POF platform, so the interaction between the analyte and the MIP's sites can be used to modulate the propagated light in the POFs and the SPR phenomena. Selectivity tests and dose-response curves by standard PFOA water solutions were carried out to characterize the detection range sensor response, obtaining a wide PFAS response range, from 1 ppt to 1000 ppt. Then, tests performed on river water samples collected from the Bormida river paved the way for the applicability of the proposed approach to a real scenario.

Optical Fiber Technology for Efficient Daylighting and Thermal Control: A Sustainable Approach for Buildings

Different direct solar harvesting systems for daylighting are being explored to achieve high uniform illumination deep within buildings at minimal cost. A promising solution to make these systems cost-effective is the use of plastic optical fibers (POFs). However, heat-related issues with low-cost POFs need to be addressed for the widespread adoption of efficient daylighting technologies. Previous studies have explored solutions for this overheating problem, but their effectiveness remains uncertain. This study proposes a low-cost fiber optic daylighting system integrated with a newly patented mechanical component designed to secure the fiber optic bundle at the focal point, providing three levels of heat filtration while ensuring uniform illumination. Our methodology involves selecting a small area, installing the setup, and measuring both heat and light readings, followed by validation through software simulations. The operational principle of this technology is explained, and experimental tests using lux meters and infrared thermometers were conducted to investigate the system’s characteristics. The three-level heat filtration device reduces temperature by approximately 35 °C at the surface of the optical fiber, and the average illumination of the room is around 400 lux. These results were further verified using RELUX simulation software. The findings demonstrate the promising potential of this new device in solar heat filtration and achieving uniform illumination. Recommendations for mitigating overheating damage and exploring heat filtering possibilities in new parabolic solar daylighting systems for further research are also provided.

Cytocidal Effects of Interstitial Photodynamic Therapy Using Talaporfin Sodium and a Semiconductor Laser in a Rat Intracerebral Glioma Model.

This preclinical study was conducted to investigate the efficacy of interstitial PDT (i-PDT) for malignant gliomas arising deep within the brain, which are difficult to remove. C6 glioma cells were implanted into the basal ganglia of rats, and 3 weeks later, the second-generation photosensitizer talaporfin sodium (TPS) was administered intraperitoneally. Ninety minutes after administration, a prototype fine plastic optical fiber was punctured into the tumor tissue, and semiconductor laser light was irradiated into the tumor from a 2-mm cylindrical light-emitting source under various conditions. The brain was removed 24 h after the i-PDT and analyzed pathologically. The optical fiber was able to puncture the tumor center in all cases, enabling i-PDT to be performed. Histological analysis showed that tumor necrosis was induced in areas close to the light source, correlating with the irradiation energy dose, whereas apoptosis was induced at some distance from the light source. Irradiation using high energy levels resulted in tissue swelling from strong tumor necrosis, and irradiation at 75 J/cm2 was most suitable for inducing apoptosis. An experimental system of i-PDT using TPS was established using malignant glioma cells transplanted into the rat brain. Tumor cell death, which correlated with the light propagation, was induced in tumor tissue.

New method for the investigation of mode coupling in graded-index polymer photonic crystal fibers using the Langevin stochastic differential equation

The mode coupling in a graded-index polymer photonic crystal fiber (GI PPCF) with a solid core has been investigated using the Langevin equation. Based on the computer-simulated Langevin force, the Langevin equation is numerically integrated. The numerical solutions of the Langevin equation align with those of the time-independent power flow equation (TI PFE). We showed that by solving the Langevin equation, which is a stochastic differential equation, one can successfully treat a mode coupling in GI PPCFs, which is an intrinsically stochastic process. We demonstrated that, in terms of effectiveness, the Langevin equation is preferable compared to the TI PFE. The GI PPCF achieves the equilibrium mode distribution (EMD) at a coupling length that is even shorter than the conventional GI plastic optical fiber (POF). The application of multimode GI PCFs in communications and optical fiber sensor systems will benefit from these findings.

Cost-effective gaze tracking system based on polymer fiber specklegrams.

Gaze tracking technology has a wide range of applications in the fields of VR/AR glasses. In this paper, a plastic optical fiber (POF) is used as a light transmission waveguide to transmit the light reflected from the eye to the outside of the device for processing, thereby eliminating the need for in-device camera installations. By processing two fan-shaped surfaces on the POF at a 45° angle relative to the vertical direction, the POF gains the ability to couple light from the side. The reflected light of the eye can be transmitted to the outside of the device through the POF. The specklegram corresponding to 76 different gaze directions is classified by SE-Resnet18, and the accuracy reached 96.9%. The gaze tracking system is low cost and simple in structure and has potential application in fields such as AR glasses, human-computer interaction (HCI), and medical diagnosis.

Structural design and performance testing of respiratory sensor based on optical fiber end-face coupling

An optical fiber sensor based on the principle of intensity modulation is proposed, which is composed of plastic optical fibers and silicone tubes. The displacement measurement is achieved by stretching the optical fibers to cause changes in the angle between the end faces, resulting in changes in the coupling efficiency between the end faces. To address the challenges in the performance calibration of fiber optic respiratory sensors, it is proposed to convert the dynamic characteristics measurement of the respiratory sensor into the static performance analysis of the displacement sensor, so as to obtain the characteristics such as sensitivity, linearity, and repeatability, etc. It is further proposed to use a stepper motor to simulate the periodic stretching process of the optical fibers caused by the respiratory process, enabling the analysis of frequency measurement accuracy under different respiratory strengths. Simulation and experimental results demonstrate that the proposed sensor has high linearity, good repeatability, high sensitivity, and a wide measurement range. It can accurately measure respiratory frequency and display amplitude information, providing comprehensive information for respiratory monitoring.

An Optical Device Based on a Chemical Chip and Surface Plasmon Platform for 2-Furaldehyde Detection in Insulating Oil.

2-Furaldehyde (2-FAL) is one of the main by-products of the degradation of hemicellulose, which is the solid material of the oil-paper insulating system of oil-filled transformers. For this reason, it has been suggested as a marker of the degradation of the insulating system; sensing devices for 2-FAL analysis in a wide concentration range are of high interest in these systems. An optical sensor system is proposed; this consists of a chemical chip, able to capture 2-FAL from the insulating oil, coupled with a surface plasmon resonance (SPR) probe, both realized on multimode plastic optical fibers (POFs). The SPR platform exploits gold nanofilm or, alternatively, a double layer of gold and silicon oxide to modulate the sensor sensitivity. The capturing chip is always based on the same molecularly imprinted polymer (MIP) as a receptor specific for 2-FAL. The system with the SPR probe based on a gold nanolayer had a higher sensitivity and a lower detection limit of fractions of μg L-1. Instead, the SPR probe, based on a double layer (gold and silicon oxide), has a lower sensitivity with a worse detection limit, and it is suitable for the detection of 2-FAL at concentrations of 0.01-1 mg L-1.

A primary simulation study of scintillating fibre dosimetry for a proton minibeam

In this paper is explored the application of optical fibre-based dosimetry in the context of charged-particles MiniBeam Radiation Therapy through comprehensive simulation analyses. A FLUKA simulation of 64 Scintillating Plastic Optical Fibre array was implemented based on a prototype built in our group. The simulations indicate that the proposed system accurately reproduces the peak-and-valley pattern of minibeams. The optical photons transport inside and between fibres was also simulated, revealing that the optical crosstalk is negligible. The resilience of the detector’s electronics under secondary radiation composed of photons and neutrons was assessed. Our results suggest the electronics’ ability to withstand the expected radiation environment in clinical accelerators. This simulation-based investigation provides valuable insights into the feasibility of optical fibre-based dosimetry for MBRT. The results show the potential of using an array of thin scintillating plastic optical fibres to determine the peak–valley dose ratio, which is a key parameter to assess the efficacy of this emerging modality.

A preliminary study of polymer optical fiber’s knittability for smart wear applications

PurposeThe purpose of this research is to ascertain the feasibility of fabricating polymer optical fibers (POFs) based textile structures by knitting with Polymethylmethacrylate (PMMA) based optical fibers for textile sensor application. It has long been established that by using the principles of physics, POFs have the capability to function as sensors, detecting strain, temperature and other variables. However, POF applications such as strain and pressure sensing using knitting techniques has since not been very successful due to a number of reasons. Commercially available PMMA-based optical fibers tend to be fragile and susceptible to breakages when subjected to stress during the knitting processes. Also light transmitted within these fibers is prone to leakage due to the curvature that results when optical fibers are interlaced or interlooped within fabric structures.Design/methodology/approachUsing Stoll’s multi-gauge CMS 350 HP knitting machine, five fabric structures namely, 1 × 4 float knit structure, tunnel inlay knit structure, 3:1 fleece fabric and 2:1 fleece fabric structure respectively were used to knit sensor samples. The samples were subsequently tested for length of illumination and sensitivity relative to applied pressure.FindingsThe results of this preliminary study establish that embedding plastic optical fibers into a knitted structure during the fabric formation process for soft strain sensor application possible. The best illumination performance was recorded for tunnel inlay structure which had an average of 94 cm course length of POF being illuminated. Sensor sensitivity experiments also establish that the relative spectral intensity of the fiber is sensitive to both light and pressure. Problems encountered and recommendations for further research have also been discussed and proffered.Research limitations/implicationsDue to resource limitations, an innovative technique (use of precision weight set) was used to apply pressure to the sensors. Consequently, information regarding the extent of corresponding sensor deformation has not been used in this initial analysis.Practical implicationsBecause the fundamental step toward finding a solution to any engineering problem is the acquisition of reliable data, and considering the fact that most of the popular technologies used for soft textile sensors are still bedeviled with the problem of signal instability and noise, the success of this application thus has the tendency to promote the wide spread adoption of POF sensors for smart apparel applications.Originality/valueAs far as research on soft strain sensors is concerned, to the best of the authors’ knowledge, this is the first study to have attempted to knit deformable sensors using commercially available POFs.

An Efficient Bio-Receptor Layer Combined with a Plasmonic Plastic Optical Fiber Probe for Cortisol Detection in Saliva.

Cortisol is a clinically validated stress biomarker that takes part in many physiological and psychological functions related to the body's response to stress factors. In particular, it has emerged as a pivotal tool for understanding stress levels and overall well-being. Usually, in clinics, cortisol levels are monitored in blood or urine, but significant changes are also registered in sweat and saliva. In this work, a surface plasmon resonance probe based on a D-shaped plastic optical fiber was functionalized with a glucocorticoid receptor exploited as a highly efficient bioreceptor specific to cortisol. The developed plastic optical fiber biosensor was tested for cortisol detection in buffer and artificial saliva. The biosensor response showed very good selectivity towards other hormones and a detection limit of about 59 fM and 96 fM in phosphate saline buffer and artificial saliva, respectively. The obtained detection limit, with a rapid detection time (about 5 min) and a low-cost sensor system, paved the way for determining the cortisol concentration in saliva samples without any extraction process or sample pretreatment via a point-of-care test.

Plasmonic Optical Fiber Sensors and Molecularly Imprinted Polymers for Glyphosate Detection at an Ultra-Wide Range

In this study, a surface plasmon resonance (SPR) sensor based on modified plastic optical fibers (POFs) was combined with a specific molecularly imprinted polymer (MIP), used as a synthetic receptor, for glyphosate (GLY) determination in aqueous solutions. Since GLY is a non-selective herbicide associated with severe environmental and health problems, detecting glyphosate in environmental and biological samples remains challenging. The selective interaction between the MIP layer and GLY is monitored by exploiting the SPR phenomenon at the POF’s gold surface. Experimental results show that in about ten minutes and by dropping microliter volume samples, the presented optical–chemical sensor can quantify up to three orders of magnitude of GLY concentrations, from nanomolar to micromolar, due to a thin MIP layer over the SPR surface. The developed optical–chemical sensor presents a detection limit of about 1 nM and can be used for onsite GLY measurements. Moreover, the experimental analysis demonstrated the high selectivity of the proposed POF-based chemical sensor.

Transformer oil temperature sensing utilizing bundle plastic optical fiber sensor

A bundle plastic optical fiber (POF) that works based on an intensity modulation technique is experimentally demonstrated to sense the temperature of transformer oil. The sensor was developed using a bundle POF that is located perpendicular to an aluminum reflective film with an airgap cavity between these two elements. The simplicity of the architecture allows the development of an economical optical sensor system. To avoid interference effects by other substances in the oil, the sensor head is encapsulated with a metal protecting tube. The temperature measurement was realized in this study by monitoring the output light intensity in the visible light spectrum. For linearity range from 40 °C to 75 °C, the tested sensor exhibits a sensitivity of 0.0064 °C−1, a linearity coefficient of 0.95 and a resolution of 1.56 °C. These results demonstrate the suitability of the developed sensor for temperature oil monitoring in an electrical power transformer system.

Splitter-Based Sensors Realized via POFs Coupled by a Micro-Trench Filled with a Molecularly Imprinted Polymer

An optical–chemical sensor based on two modified plastic optical fibers (POFs) and a molecularly imprinted polymer (MIP) is realized and tested for the detection of 2-furaldehyde (2-FAL). The 2-FAL measurement is a scientific topic of great interest in different application fields, such as human health and life status monitoring in power transformers. The proposed sensor is realized by using two POFs as segmented waveguides (SW) coupled through a micro-trench milled between the fibers and then filled with a specific MIP for the 2-FAL detection. The experimental results show that the developed intensity-based sensor system is highly selective and sensitive to 2-FAL detection in aqueous solutions, with a limit of detection of about 0.04 mg L−1. The proposed sensing approach is simple and low-cost, and it shows performance comparable to that of plasmonic MIP-based sensors present in the literature for 2-FAL detection.

Plastic Optical Fiber Sensor for Sensing Refractive Index of Citric Acid Based on Surface Plasmon Resonance

Using plastic optical fiber with multimode (MPOF), an optical fiber sensor (OFS) based on Surface Plasmon Resonance (SP.R) was created and put into use. The sensor is used to determine performance metrics including signal to noiseratio (SNR), Sensitivity(S), Figure of merit(FOM), and Resolution(R) in addition to detecting and measuring the refractive index of different concentrations of citric acid. With a sensing region exposed to 50 nm of gold (Au) metal layer, the optical fiber-based SPR sensor was found to have a sensitivity value of 1250nm, an SNR of 0.27, a figure of merit of 93.3 and a resolution 8×10-4.

Thermal stability of light transmission on tapered plastic optical fibre coated with PMMA/zircon composites

Abstract A study on thermal stability of light transmission on tapered plastic optical fibre (TPOF) due to PMMA/zircon composites coating has been performed. The zircon filler was obtained from purified local zircon sand. The PMMA/zircon composites were produced utilizing acetone at a temperature of 50°C. The TPOF was subjected to a dip coating procedure to apply composite coatings at varying zircon of 0, 0.5, and 1 wt.%. The characterization of light transmission on coated the TPOF, investigated at an environmental temperature range of 30 to 60°C, was conducted using an optical power meter (OPM) and a spectrometer. Based on the OPM measurements, it is known that the output power of the composite coated TPOF exhibits a high degree of linearity, even when subjected to varying environmental temperatures. The coated composite material also exhibits the capability to withstand wavelength peak shift. Therefore, it can be inferred that the composites could resist fluctuations in external temperatures. To fulfil additional objectives, the composite material can be employed as a protective layer for TPOF applications, particularly while operated at temperatures exceeding the ambient conditions.

Plasmonic sensor combined with a microcuvette device for monitoring molecule binding processes at ultra-low concentrations

A novel sensing strategy is presented to monitor receptor-target pair interactions at ultra-low concentrations without functionalization processes. The biosensing is made by a sensitive chip and a surface plasmon resonance (SPR) probe connected in series, both built up on multimode plastic optical fibers (POFs). The SPR probe is a conventional D-shaped POF platform, while the capture platform consists of three microholes, containing a few hundred nanoliters each, made in the core of a modified POF. The microholes are filled with a specific receptor solution, which selectively captures the target present in the samples dropped over the filled microholes. Any variation occurring in the microholes due to the molecule binding processes changes the mode profile of the propagated light in the POF's core, modifying the plasmonic effects proportionally to the phenomena under scrutiny. As a proof of concept, the interactions of two receptor-target pairs, estradiol and cortisol to the respective receptors, namely Estrogen Receptor alpha protein (ER) and Glucocorticoid Receptor (GR), were monitored over time in the attomolar range. The receptor-target pair interactions are observed at ultra-low concentrations (order of aM) by monitoring the resonance wavelength shift over time. The proposed sensing approach stands for a novel class of laboratory instrumentation with unprecedented capabilities in terms of compactness, ultra-high sensitivity and low-cost.

Highly-Sensitive Polymer Optical Fiber SPR Sensor for Fast Immunoassay

A new type of human immunoglobulin G (IgG) sensors based on the surface plasmon resonance (SPR) in the low refractive index (RI) plastic optical fiber (POF) and an antibody immobilization method is presented. A 50-nm-thick gold film was formed on the polished D-shaped fiber surface by magnetron sputtering. The RI response of the POF sensor is 30 049.61 nm/RIU, which is 26.5 times higher than that of single mode fiber (SMF) SPR sensors. The proposed SPR biosensor can be developed by simple and rapid modification of the gold film with 11-mercapto undecanoic acid (MUA). Upon immobilization of the goat anti-human IgG antibody, the resonance wavelength shifts by 11.2 nm. The sensor can be used to specifically detect and quantify the human IgG at concentrations down to 245.4 ng/mL with the sensitivity of 1.327 7 nm per µg/mL, which offers an enhancement of 12.5-fold compared to that of the conventional SMF based SPR sensors. The proposed device may find the potential applications in the case of use at the point of care.

Plastic optical fibers as optical illuminators for digital holography and structured fringe patterns generation

Plastic optical fibers as optical illuminators for digital holography and structured fringe patterns generation