Optical fiber sensors

Semakin banyak instansi yang mulai beralih menggunakan kabel fiber optik sebagai media transmisinya. Keunggulannya terletak pada kecepatan transfer data dan bebas interferensi karena menggunakan media cahaya dalam pentransmisian datanya. Oleh karena penggunaannya yang semakin meluas, maka penulis membuat aplikasi yang mampu mendeteksi apabila terjadi putus dan bending (pembengkokan)  pada kabel fiber optik tersebut. Parameter yang digunakan adalah RTT (Round Trip Time). Nilai RTT<1ms, program akan mendeteksi  kabel optik kondisi normal. Nilai RTT>1ms, program akan mendeteksi kabel optik bengkok. Tidak ada reply, program akan mendeteksi kabel putus. Warning message akan dikirimkan menggunakan sistem SMS Gateway ke nomor handphone teknisi jika terjadi bending atau putus jaringan. Pengujian aplikasi dilakukan dan kemudian dibandingan dengan hasil pengujian dan pengukuran  menggunakan powermeter, OTDR, dan light source. Dengan menggunakan powermeter, hasil pengukuran loss jika kabel optik dalam kondisi normal adalah  -2,1 dBm sedangkan jika ditekuk (bend)loss menjadi -30,51 dBm.Dengan menggunakan OTDR didapat nilai total loss jaringan fiber optik ini adalah 0.037 dBm. Aplikasi dapat mendeteksi kondisi normal dan putus dengan benar sementara untuk kondisi bending, aplikasi tetap mendeteksinya sebagai kondisi normal.
Kata Kunci: fiber optik, RTT (Round Trip Time), bending, SMS Gateway, warning message

The Optical Fibers and Their Applications 2018 conference is a forum of national
science in this branch of Photonics. The conference usually hosts numerable guests
from this geographic region, especially from Ukraine, Belarus and Kazakhstan. It is
organized every year and a half by two major optical fiber technology and
application centers located in Białystok at Białystok University of Technology, and
in Lublin, at Maria Curie-Skłodowska University and Technical University of Lublin.
The conference belongs to a bigger circle of national conferences on
optoelectronics, optics, photonics, sensors and laser technology, which are under
the general patronage of professional community organizations like the Polish
Ceramic Society, Photonics Society of Poland, Polish Optoelectronics Committee
of the Association of Polish Electrical Engineers, and the Section of Optoelectronics
in the Committee of Electronics and Telecommunications, Polish Academy of
Sciences.

This paper demonstrates a rapid, cost-effective and field-portable smartphone based turbidimeter that measures turbidity of water samples collected from different natural water resources and in drinking water. The working of the designed sensor is based on a Mie-scattering principle where suspended micro (m-) particles in water medium scatter a strong light signal along the normal direction of the incoming light signal, which can be detected by an infra-red (IR) proximity sensor embedded in the smartphone. Two freely available android applications were used to measure the irradiance of the scattered flux and analyse the turbidity of the medium. With the designed sensor, water turbidity variation as low as 0.1 NTU can be measured accurately in the turbidity value ranging from 0 to 400 NTU. The sensor responses for these ranges of turbid media are found to be linear. A high repeatability in the sensor characteristics is also been observed. The optics design involved for the development of the proposed smartphone turbidimeter is simple and is robust in operation. The designed sensing technique could emerge as a truly portable, user-friendly and inexpensive turbidity sensing tool that would be useful for different in-field applications.

Finite-difference time domain (FDTD) method was used to investigate the performance of surface plasmon resonance (SPR)-based optical fiber sensors. The results show that the performance of the fiber sensor can be optimized by choosing a proper combination of metal layer thickness of 40e60 nm and residual cladding thickness of 400e500 nm. Furthermore, the roughness effect of the gold surface layering the fiber sensor is significant in rough surfaces when sigma rms is greater than 5 nm or correlation length is lower than 100 nm.

The temperature resolution of a fibre-optic distributed temperature sensor based on taking the ratio of the temperature sensitive backscattered spontaneous Brillouin signal to the corresponding Rayleigh signal depends on the optical signal-to-noise of the receiver system and the amplitude fluctuations in the Rayleigh signal. The amplitude fluctuations or coherent Rayleigh noise have been investigated experimentally as a function of detection bandwidth, source bandwidth and spatial resolution and showed good agreement with theory.

Demand for online and real-time measurements techniques to meet environmental regulation and treatment compliance are increasing. However the conventional techniques, which involve scheduled sampling and chemical analysis can be expensive and time consuming. Therefore cheaper and faster alternatives to monitor wastewater characteristics are required as alternatives to conventional methods. This paper reviews existing conventional techniques and optical and fibre optic sensors to determine selected wastewater characteristics which are colour, Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). The review confirms that with appropriate configuration, calibration and fibre features the parameters can be determined with accuracy comparable to conventional method. With more research in this area, the potential for using FOS for online and real-time measurement of more wastewater parameters for various types of industrial effluent are promising.

The thermoluminescence (TL) glow curves and kinetics parameters of Thulium (Tm) doped silica cylindrical fibers (CF) are presented.  A linear accelerator (LINAC) was used to deliver high-energy radiation of 21 MeV electrons and 10 MV photons.  The CFs were irradiated in the dose range of 0.2 Gy – 10 Gy. The experimental glow curve data was reconstructed by using WinREMS.  The WinGCF software was used for the kinetic parameters evaluation.  The TL sensitivity of Tm-doped silica CF is about 2 times higher as compared to pure silica CF.  Tm-doped silica CF seems to be more sensitive to 21 MeV electrons than to 10 MV photons.  Surprisingly, no supralinearity was displayed and a sub-linear response of Tm-doped silica CF was observed within the analysed dose range for both 21 MeV electrons and 10 MV photons.  The Tm-doped silica CF glow curve consists of 5 individual glow peaks.  The Ea of peak 4 and peak 5 was highly dependent on dose when irradiated with photons.  We also noticed that the electron radiation (21 MeV) caused a shift of glow peak by 7 – 13 oC to the higher temperature region compared with photons radiation (10 MV).  Our Tm-doped fibers seem to give high TL response after 21 MeV electrons, which gives around 2 times higher peak integral as compared with 10 MV photon radiation.  We concluded that Peak 4 is the first-order kinetic peak and can be used as the main dosimetric peak of Tm-doped silica CF.

—We report the fabrication of a multimode interferom-eter (MMI), based on a multimode polymer optical fiber (POF), sandwiched between two single-mode silica fibers. The POF used in this work is a step-index fiber with core and cladding composed of a cycloolefin polymer (COP) and PMMA, respectively. The low moisture absorption of the COP material and the benefit of having an exposed core for refractive index measurements in MMI devices lead us to perform an etching of the PMMA layer. Additionally, we report the inscription of a Bragg grating in the COP core material of an etched single-mode-multimode-single-mode (SMS) structure. The two fiber structures were simultaneously characterized to strain, temperature, humidity, and refractive index. The ability to detect refractive index by using a POF-based SMS structure is reported for the first time in this paper. Additionally, the capability for dual parameter measurement was discussed using both FBG and SMS structures. Index Terms—Etching, fiber Bragg grating (FBG), multimode interference (MMI), optical fiber sensor, plastic optical fiber (POF).

is to bring together professionals, academics and students who are interested in the advancement of research and practical applications of human-technology & human-computer interaction. Five parallel tracks will be held, covering different aspects of Computer-Human Interaction, including Interaction Design, Human Factors, Entertainment, Cognition, Perception, User-Friendly Software and Systems, Pervasive Technologies and Interactive Devices. Papers describing original work on advanced methods, prototypes, systems, tools and techniques as well as general survey papers indicating future directions are encouraged. Accepted papers will be presented at the conference by one of the authors and published in the Proceedings of CHIRA, which will be placed on at least one Digital Library and sent for indexation by the major international indexes. CONFERENCE AREAS Each of these topic areas is expanded below but the sub-topics list is not exhaustive. Papers may address one or more of the listed sub-topics, although authors should not feel limited by them. Unlisted but related sub-topics are also acceptable, provided they fit in one of the following main topic areas:

Groundwater is the major source of drinking water for people living in rural areas of India. Pollutants such as fluoride in groundwater may be present in much higher concentration than the permissible limit. Fluoride does not give any visible coloration to water, and hence, no effort is made to remove or reduce the concentration of this chemical present in drinking water. This may lead to a serious health hazard for those people taking groundwater as their primary source of drinking water. Sophisticated laboratory grade tools such as ion selective electrodes (ISE) and portable spectrophotometers are commercially available for in-field detection of fluoride level in drinking water. However, such tools are generally expensive and require expertise to handle. In this paper, we demonstrate the working of a low cost, robust, and field portable smartphone platform fluoride sensor that can detect and analyze fluoride concentration level in drinking water. For development of the proposed sensor, we utilize the ambient light sensor (ALS) of the smartphone as light intensity detector and its LED flash light as an optical source. An android application " FSense " has been developed which can detect and analyze the fluoride concentration level in water samples. The custom developed application can be used for sharing of in-field sensing data from any remote location to the central water quality monitoring station. We envision that the proposed sensing technique could be useful for initiating a fluoride removal program undertaken by governmental and nongovernmental organizations here in India.

Finite-difference time domain (FDTD) method was used to investigate the performance of surface plasmon resonance (SPR)-based optical fiber sensors. The results show that the performance of the fiber sensor can be optimized by choosing a proper combination of metal layer thickness of 40e60 nm and residual cladding thickness of 400e500 nm. Furthermore, the roughness effect of the gold surface layering the fiber sensor is significant in rough surfaces when sigma rms is greater than 5 nm or correlation length is lower than 100 nm.

The Smart Driving Skill Evaluation (SDSE) System presented in this paper expedite the testing of candidates aspiring for a driving license in a more efficient and transparent manner, as compared to the present manual testing procedure existing in most parts of Asia and Pacific region. The manual test procedure is also subjected to multiple limitations like time consuming, costly and heavily controlled by the experience of examiner in conducting the test. This technological solution is developed by customizing 8051 controller based embedded system and LabVIEW based virtual instrument. The controller module senses the motion of the test vehicle on the test track referred to as zero rpm measurement and the LabVIEW based virtual instrument provides a Graphical User Interface for remote end monitoring of the sensors embedded on the test track. The proposed technological solution for the automation of existing manual test process enables the elimination of human intervention and improves the driving test accuracy while going paperless with Driving Skill Evaluation System. As a contribution to the society this technological solution can reduce the number of road accidents because most accidents results from lack of planning, anticipation and control which are highly dependent on driving skill.

In order to further understand the contribution of venous and arterial effects to the photoplethysmographic (PPG) signal, recordings were made from 20 healthy volunteer subjects during an exercise in which the right hand was raised and lowered with reference to heart level. Red (R) and infrared (IR) PPG signals were obtained from the right index finger using a custom-made PPG processing system. Laser Doppler flowmetry (LDF) signals were also recorded from an adjacent fingertip. The signals were compared with simultaneous PPG signals obtained from the left index finger. On lowering the hand to 50 cm below heart level, both ac and dc PPG amplitudes from the finger decreased (e.g. 18.70 and 63.15% decrease in infrared dc and ac signals respectively). The decrease in dc amplitude most likely corresponded to increased venous volume, while the decrease in ac PPG amplitude was due to regulatory adjustments on the arterial side in response to venous distension. Conversely, ac and dc PPG amplitudes increased on raising the arm above heart level. Morphological changes in the ac PPG signal are thought to be due to vascular resistance changes, predominately venous, as the hand position is changed.

We report here for the first time the fabrication and characterization of mechanically induced ultralong period fiber gratings (MULPFG) with period size up to several millimeters. In these gratings the coupling of the fundamental guided core mode takes place with cladding modes of high diffraction orders.The transmission characteristic of grating with different external applied pressure has been experimentally verified.

Photonic crystal fibre (PCF)–fibre bragg grating (FBG) integration opens up new possibilities in multi-parameter fibre-optic sensing, owing to their active control over light characteristics and mode confinements. Their integration results in a mismatch in their mode field diameters (MFDs), which in turn causes various types of losses such as confinement loss, scattering loss, etc. This paper primarily investigates the effect of geometrical parameters on fibre parameters such as confinement loss and MFD, which plays a significant role in long distance fibre-optic remote sensing. Liquid crystal PCFs (LCPCFs) are utilized in the sensor configuration, exploiting their optical properties for photonic bandgap based tighter mode confinements and wavelength tunability. Furthermore, the LCPCF–FBG combo enables multi-parameter fibre-optic sensing which can be effectively utilized in oil and gas sensing applications. Theoretical study conducted on the fibre sensor revealed that confinement loss and MFD can be reduced by properly optimizing their structural parameters.

O objetivo deste projeto, que se insere no contexto da importância de se aprofundar o conhecimento sobre a dinâmica dos bioprocessos e sobre os instrumentos de análise e monitoramento disponíveis, foi a compilação e análise da modelagem matemática proposta por Atala et al. (2001) e a simulação dinâmica do processo de fermentação alcóolica em batelada, utilizando o software livre Scilab 5.5.2 (ESI Group, França), e sua ferramenta Xcos. Experimentos de fermentação foram conduzidos, mantendo-se a temperatura do meio constante, e foi realizando o monitoramento da concentração de sacarose por meio de viscosimetria capilar e por meio de sensoriamento por fibra óptica baseado na variação da intensidade refletida. Utilizando o modelo matemático de Atala et al. (2001), estes dados foram utilizados para estimar curvas de crescimento celular, e as curvas obtidas destas formas foram, por fim, comparadas a cada uma das curvas teóricas, calculadas pelo simulador dinâmico. Consistiu, portanto, em um projeto de cunho prático, com objetivo de verificar a validade do uso de metodologia comumente empregado nas indústrias brasileiras, especialmente quando há carência de recursos financeiros para a aquisição de instrumentos mais refinados. Muitas vezes, o uso destes equipamentos de alta performance acaba restrito às aplicações mais sensíveis, como o controle de qualidade, sendo que a operação do processo precisa trabalhar com medições de propriedades físico químicas mais simples.

We introduce the idea of optical fibers made up of single negative metamaterial photonic crystal cladding with zero effective phase bandgap. Fiber characteristics are analyzed both at sub-wavelength and non sub-wavelength crystal dimension by varying cladding thickness and core radius. We find that in both cases they are robust with respect to incident angle, polarization of the light, crystal constant, and cladding irregularities. The fiber is found to behave like a step index fiber but the guided modes are leaky like Bragg fiber. It is shown that a fixed cladding thickness produces fixed loss around impedance matching frequency irrespective of crystal constant.

Recent advances in the design and implementation of wearable resistive, capacitive, and optical strain sensors are summarized herein. Wearable and stretchable strain sensors have received extensive research interest due to their applications in personalized healthcare, human motion detection, human–machine interfaces, soft robotics, and beyond. The disconnection of overlapped nanomaterials, reversible opening/closing of microcracks in sensing films, and alteration of the tunneling resistance have been successfully adopted to develop high‐performance resistive‐type sensors. On the other hand, the sensing behavior of capacitive‐type and optical strain sensors is largely governed by their geometrical changes under stretching/releasing cycles. The sensor design parameters, including stretchability, sensitivity, linearity, hysteresis, and dynamic durability, are comprehensively discussed. Finally, the promising applications of wearable strain sensors are highlighted in detail. Although considerable progress has been made so far, wearable strain sensors are still in their prototype stage, and several challenges in the manufacturing of integrated and multifunctional strain sensors should be yet tackled.

Abstract—We report distributed temperature measurements based on Raman scattering performed during steady state gamma-ray irradiation at a dose rate of 1 kGy(SiO 2)/h and up to a total ionizing dose (TID) of ~ 0.1 MGy. We characterize on-line the evolution of the performances of a single-ended Raman distributed temperature sensor (RDTS) during the -ray exposure of different classes of commercial multimode fibers (MMFs) acting as the sensing element. RDTS is influenced by the radiation-induced attenuation (RIA) phenomena leading to both large errors in the temperature measurements and a diminution of the useful sensing length. The amplitude of the radiation-induced temperature error strongly depends on the fiber choice and on the irradiation conditions. For the single-ended RDTS operation in the targeted Cigéo application the selection of a radiation tolerant sensing fiber will be mandatory, but not sufficient, to overcome the expected severe ambient conditions around radioactive wastes. For efficient temperature sensing up to an accumulated dose of 0.1 MGy, pre-irradiation of the selected radiation resistant (RR) fibers appears also necessary to improve the sensor performances.

Mid-infrared (mid-IR) optical fibers have long attracted great interest due to their wide range of applications in security, biology and chemical sensing. Traditionally, research was directed towards materials with low absorption in the mid-IR region, such as chalcogenides, which are difficult to manipulate and often contain highly toxic elements. In this paper, we demonstrate a Polyethylene Terephthalate Glycol (PETG) hollow-core fiber (HCF) with guiding properties in the mid-IR. Guiding is provided by the fiber geometry, as PETG exhibits a material attenuation 2 orders of magnitude larger than the HCF propagation loss. The structured plastic fiber preforms were fabricated using commercial 3D printing technology and then drawn using a conventional fiber drawing tower. The final PETG fiber outer diameter was 466 µm with a hollow-core diameter of 225 µm. Thermal imaging at the fiber facet performed within the wavelength range 3.5–5 µm clearly indicates air guidance in the fiber hollow-core. Since the invention of laser sources in the mid-IR range spectral region (2.5 to 25 μm), there has been a growing interest in the development of optical fibers transparent at these wavelengths for applications in chemical, biological and atmospheric sensing 1–4 , where the unique molecular absorption associated to the excitation of specific fundamental vibrational and rotational modes allows for an accurate chemical fingerprinting 5. Although over the last 3 decades silica optical fibers have become the backbone of optical communications and distributed optical sensing, they cannot guide light in the mid-IR as the silica network has strong overtone absorptions above 2 μm, resulting in an overall attenuation that increases for increasing wavelengths. Thus, the search for optical fiber operating in the mid-IR has focused on materials that have high transmittance in the wavelength range λ = 2–20 μm such as chalcogenide glasses, heavy metal fluorides, polycrystalline silver halides (AgX), single-crystal sapphire, and tellurium halides (TeX) 6–8 , which still requires extraordinary purification processes and are extremely hard to handle. An alternative approach relies on the use of hollow-core fibers (HCFs) such as photonic bandgap fibers and anti-resonant fibers, where light is confined within the hollow-core, greatly decreasing the influence of the material optical properties. Such fibers have been already exploited for numerous applications in infrared spectroscopy such as laser surgery, gas sensing, label-free biological sensing, thermal imaging and infrared countermeasures 9–13. In initial attempts, mid-IR HCFs have been fabricated by coating the inner surface of a capillary tube with a metallic film and dielectric material. However, the coating procedure is relatively cumbersome and used toxic materials. Lately, pure silica HCFs have been investigated 14. As the mode propagates in the microstructured fiber hollow-core, the effect of the silica's high material absorption is minimized owing to the low overlap (<1%) of the guided mode with the glass. Silica HCFs were manufactured using the stack and draw technique, where capillaries are manually assembled into a hexagonal structure prior to draw. Despite this being the most popular method, it is labor intensive, mainly limited to the hexagonal packed periodic structure and difficult to implement for complex designs. Because of the continuous improvement in additive manufacturing technologies and the related cost reduction , the fabrication of prototypes using 3D printing has gained interest in many applications such as medical , art, engineering and science. The most common manufacturing techniques to print 3D models include

The main project aims is to monitor the mechanical responsivity of the wooden long bow and arrow using optical fiber bragg grating sensors (FBGs). The project considers the time constraint and the availability of the equipments in the lab to develop the sensor system to access the strain endure by the wooden long bow during drawing back. We build a general connecting circuit along the wooden long bow with FBG sensor which consists of optical fiber amplifier, coupler, spectral analyser and optic fiber. The experiment aims to answer the following questions in detail: The relative difference in measurement between tape (3M Micropore TM Tape) and the glue (M.Bond 200 [Vishay] Adhesive which contains cyanocrylate ester) and the strengths and weakness of the tape and glue. The test depends on the strain of the bow. Manual recordings from the Optical Spectrum Analyser (OSA) will be taken to see the shift in wavelength as strain is applied.

We study the characteristics of the FBG Sensors, photodiode, Erbium Amplifier, the relation between responsivity and wavelength. We also analyse the linearity and power level changes that takes place once the Erbium Amplifier is introduced into the circuit. From previous papers, we understand FBG technique is more accurate and reliable for the measurements and discuss the future of it.

We propose a novel Surface Plasmon Resonance (SPR)-based sensor that detects dew formation in optical fiber-based smart textiles. The proposed SPR sensor facilitates the observation of two phenomena: condensation of moisture and evaporation of water molecules in air. This sensor detects dew formation in less than 0.25 s, and determines dew point temperature with an accuracy of 4%. It can be used to monitor water layer depth changes during dew formation and evaporation in the range of a plasmon depth probe, i.e., 250 nm, with a resolution of 7 nm. Further, it facilitates estimation of the relative humidity of a medium over a dynamic range of 30% to 70% by measuring the evaporation time via the plasmon depth probe.

We have experimentally investigated the multi-parameter sensing characteristics in a novel all-fiber Sagnac loop hybrid interferometer based on a highly birefringent photonic crystal fiber with two asymmetric cores. The sensor device was based on a combination of two types of in-fiber interferences, the intra-core-mode Sagnac interference and the inter-coremode Mach-Zehnder interference due to the distinct birefringent properties associated with the asymmetric cores. Fast Fourier transform analysis on the transmission spectra of the device exhibited six clear peaks in the spatial frequency domain. By examining the phase shift responses of two distinct Sagnac and one Mach-Zehnder interference peaks, the response matrix that enable simultaneous measurement of torsion, strain, and temperature could be obtained. The proposed all-fiber Sagnac loop hybrid interferometer has the advantages such as simplicity of the device structure, compact device size, and capability for simultaneous sensing of multiple parameters.

Microstructured polymer fibers (mPOF) are being fabricated in the Speciaty Optical Fibers Laboratory (LaFE) at the State University of Campinas (UNICAMP) in Brazil. In this work the initial results will be presented , in particular those related with a single mode fiber, a bimodal fiber, a spun fiber with elliptical birefrin-gence and a two cores fiber made with PMMA cladding and cyclo olefin cores.

This paper reports a hexagonal microstructure optical fiber design which attains ultra-high birefringence property with high negative dispersion in a wideband transmission system. The finite element method with circular perfectly matched boundary layer is used to examine the guiding properties. According to simulation it is demonstrated that, the proposed hexagonal microstructure optical fiber (H-MOF) deals with high birefringence of 3.373×10-2. The proposed fiber achieves negative dispersion coefficient of −837.8 ps/(nm.km) and also high nonlinear coefficient of 53.45 W-1 km-1 is obtained at 1550 nm wavelength. The fiber possesses excellent guiding properties which has the capability of sensing and dispersion compensation in high-bit-rate transmission network.

A hand-elevation study was carried out in the laboratory in order to alter peripheral blood flow with the aim of increasing understanding of factors affecting the morphology of peripheral photoplethysmographic signals. Photoplethysmographic (PPG) signals were recorded from twenty healthy volunteer subjects during a hand-elevation study in which the right hand was raised and lowered relative to heart level, while the left hand remained static. Red and infrared (IR) PPG signals were obtained from the right and left index fingers using a custom-made PPG processing system. PPG features were identified using a feature-detection algorithm based on the first derivative of the PPG signal. The systolic PPG amplitude, the reflection index, crest time, pulse width at half height, and delta T were calculated from 20 s IR PPG signals from three positions of the right hand with respect to heart level (-50, 0, ?50 cm) in 19 volunteers. PPG features were found to change with hand elevation. On lowering the hand to 50 cm below heart level, ac systolic PPG amplitudes from the finger decreased by 68.32 %, while raising the arm increased the systolic amplitude by 69.99 %. These changes in amplitude were attributed to changes in hydrostatic pressure and the veno-arterial reflex. Other morphological variables, such as crest time, were found to be statistically significantly different across hand positions, indicating increased vascular resistance on arm elevation than on dependency. It was hypothesized that these morphological PPG changes were influenced by changes in downstream venous resistance, rather than arterial, or arteriolar, resistance. Changes in hand position relative to heart level can significantly affect the morphology of the peripheral ac PPG waveform. These alterations are due to a combination of physical effects and physiological responses to changes in hand position, which alter vascular resistance. Care should be taken when interpreting morphological data derived from PPG signals and methods should be standardized to take these effects into account.

ANALISA PERFORMANSI ARRAY WAVEGUIDE GRATING (AWG)  PADA JARINGAN WAVELENGTH DIVISION MULTIPLEXING (WDM) GIGABIT-PASSIVE OPTICAL NETWORK  (GPON)


AFIF SAIFUDDIN
10955005522

Tanggal Sidang : 19 Desember 2013

Jurusan Teknik Elektro
Fakultas Sains dan Teknologi
Universitas Islam Negeri Sultan Syarif Kasim Riau
Jl. Soebrantas No. 155 Pekanbaru

ABSTRAK

Serat optik merupakan media transmisi yang mempunyai kapasitas dan kecepatan yang tinggi. Dengan mengimplementasikan Wavelength Division Multiplex dan Gigabit Passive Optical Network akan menghasilkan jaringan dengan bandwidth dan kecepatan yang tinggi. Penggunaan Arrayed Waveguide Grating digunakan sebagai multiplexer dan demultiplexer-nya dalam rangka untuk menghasilkan performansi yang lebih baik terhadap sistem. Pada penelitian ini dilakukan analisa terhadap berapa channel spacing yang bisa diterapkan pada model sistem, jarak transmisi maksimum, serta berapa panjang gelombang maksimum yang bisa dimultipleks pada sistem ini. Di samping itu juga dilakukan analisa terhadap perbandingan nilai BER untuk model sistem yang menggunakan AWG dengan yang menggunakan multiplexer konvensional. Dari hasil simulasi yang diperoleh, channel spacing minimum yang bisa diterpkan pada model sistem adalah 0,1 nm dengan jarak transmisi maksimum mencapai 90 km tanpa menggunakan repeater. Jumlah saluran atau panjang gelombang yang bisa dimultipleks-kan pada sistem adalah 64 saluran. Dibandingkan dengan penggunaan multiplexer konvensional, penggunaan AWG menghasilkan nilai BER yang lebih kecil sehingga mempunyai performansi yang lebih baik.

Kata Kunci : Arrayed Waveguide Grating, Wavelength Division Multiplex, Gigabit Passive Optical Network.

In this study, an easy to construct and sensitive intracavity fiber loop ring down spectrometer was built by
commercially available basic components and its application on chemical sensing is presented. System
performance was investigated by using various acetylene/nitrogen gas mixtures as a function of total pressure
(between 25 and 65 psia) in sensing region and a calibration curve is established. The instrument can achieve a
limit of detection of 0.1% without a FBG and/or EDFA or a need for a complicated design. Moreover, the
detection limit can be further improved by working at higher pressures. With the current design of the system,
the change in type and/or concentration of species in the sensor region can be monitored in real time.

Optical fiber sensors have become a widely used tool to perform life-long
monitoring of large structures. Different set-ups of sensors can be used to obtain
information at different scopes. In this paper, the application of a portable Brillouin
optical time domain analysis sensor applied to reinforced concrete beams is
presented. The sensor is made up of a single-mode optical fiber applied to the
structure that enables the measurement of tensile and compressive axial strain along
the beams. The fiber is embedded into a concrete casting without particular
installation care and fixed along the reinforcement bars so that a complete correlation
can be obtained regarding axial strain and displacements at different heights of the
beam in linear and non-linear bending response. The use of four sensing fibers
positioned along the beam's length at different vertical positions makes it possible to
read the strain variation within the cross-section. In accordance with Bernoulli’s
hypothesis, this allows curvature diagrams to be obtained across the structure. The
measured curvature is used to set up the moment–curvature relationship, which
highlights the possibility of the sensor monitoring structures continuously in space
and time. From the experiment the theoretical and experimental results are compared
and it will be seen how they can actually be reliable in order to perform a monitoring
on civil engineering structures. This allows to validate the response of a distributed
fiber optic sensor and to promote its use for structural health monitoring (SHM).

— An all-fiber high-sensitivity modal interferometer formed by a bent standard single-mode fiber (SMF) has been presented and demonstrated, which can be used to measure refractive indexes (RIs) of solutions and temperature. The interferometer has a simple and compact structure built with a bent bare SMF mimicking a balloon shape. Because of the curvature of bent fiber sensor, modal interference effect would occur when light propagates from the fiber core into the cladding. The measurement is achieved by monitoring the spectral shift of the modal interference. The performances of the interferometers with different bending diameters and sensitive lengths are experimentally investigated concluding the optimal bending radius as 4 mm and sensitive length 16 mm. In the RI range of 1.3493–1.3822, the corresponding sensitivity and detection limit are 225.95 nm/RIU (refractive index unit) and 3.2×10 −4 , respectively. The temperature sensitivity and detection limit of 0.418 nm/°C and 0.173 °C are achieved, respectively. Index Terms— Balloon-like interferometer, bent single-mode fiber, refractive index (RI) sensing, temperature sensing.

Symposium on “Optical Fibers and Their Application” OFTA is a forum of national
science in this branch of Photonics. The Symposium also hosts numerable guests
from this geographical region, and especially from neighboring countries and
Europe. It is organized every year and a half by two major optical fiber technology
and application development centers located in Białystok at Białystok University of
Technology, and in Lublin at Maria Curie-Skłodowska University UMCS and the
Technical University of Lublin. The conference belongs to a bigger circle of national
meetings on optoelectronics, optics, photonics, sensors and laser technology
which are under a general patronage of professoressional community
organizations like the Polish Physical Society – Section of Optics, the Polish Ceramic
Society, the Photonics Society of Poland, Polish Optoelectronics Committee of the
Association of Polish Electrical Engineers, Section of Photonics in the Committee of
Electronics and Telecommunications, Polish Academy of Sciences, and Polish
Association of Theoretical and Applied Electrical Engineering.

Herein, we present a study of the use of polymer capillary optical fibers in sensing measurements. In particular, we approach the application of these fibers for temperature sensing. To do this, an analytical model for describing the spectral characteristics of the light transmitted through the capillaries was employed. Thermal expansion and thermo-optic effect influences on the transmitted spectrum were evaluated. Moreover, a 140 ± 6 pm/ºC temperature sensitivity was measured, which is in good resemblance to simulated data and is around 14 times higher than the sensitivity attained in conventional Bragg gratings sensors.

We report on the wavelength and time-domain responses of a lumped or distributed fiber-optic modalmetric interferometer under a very smooth pressure (fingerprint) disturbances in the 1530–1610 nm wavelength range. A simple method to quantify such disturbances is proposed. It is shown that the lateral offset shift of 5.9 um between the single-mode and the multimode fiber splice makes the device even more sensitive. It was measured an electrical signal power enhancements of 3.5 and 7.5 dB for 1 m and 1.65 km multimode fiber link, respectively.

We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

Purpose – The purpose of this paper is to provide a comparative review of intensity-modulated fiber optic sensors with non-optical sensors for health monitoring applications, from the current research activities in the area. Design/methodology/approach – A range of published research work in sensor design for four different health monitoring applications, including, lumbar spine bending, upper and lower limb motion tracking, respiration and heart rate monitoring, are presented and discussed in terms of their respective advantages and limitations. Findings – This paper provides information on the various types of sensors applied into the health monitoring area. The sensing techniques of the fiber optic sensor for the stated applications are focused and compared in details to highlight their contributions. Originality/value – A comparative review of published work is illustrated in an informative table content, to allow a clear idea of the current sensing approaches for health monitoring applications.

The force myography (FMG) is a method for retrieving the hand movements by assessing the radial forces exerted by the forearm muscles. In this context, optical fiber transducers based on different principles (microbending, LPFG, specklegram, and hetero-core structure) are evaluated for the measurement of FMG signals. Furthermore, the microbending transducer was applied on gesture recognition for the real-time control of a virtual prosthetic hand. The sensor presented ~0.05 N −1 sensitivity for a 20 N range and was successfully implemented on the classification of 4 postures, providing a low-cost and reliable approach for controlling multi-grasp bionic hands.

Wireless Ad-Hoc Mesh Networks are characterized by static nodes connected in a mesh topology. A routing protocol discovers and maintains the route for successful transmission of data in a network. The routing protocol should also provide load balancing and fault tolerance for improved network performance. In Free Space Optical networks (FSO) line of sight (LOS) should be maintained between the two communicating nodes. In a multihop scenario maintaining LOS during routing is a challenge. In this paper we propose a routing protocol Quality of Service-Directional Routing Protocol (QDRP)-which assures a certain level of performance to a data flow in terms of delay and implemented on FSO MANET. Through simulations it is observed that QDRP chooses the path with the least delay and performs satisfactorily under varying node densities and transmission rates achieving end to end delay of .14 s and packet delivery percentage of 96% when simulated for an area of 1300 m *1300 m for 100 nodes. This work explores the potential of the proposed routing protocol for free space optical mesh networks. QDRP is compared with ORRP (Orthogonal Rendezvous Routing Protocol) and AODV (Ad-Hoc on Demand Distance Vector), a reactive protocol which is also implemented in free space optical environment. We support our conclusions that QDRP gains in terms of packet delivery percentage, end to end delay and goodput.

The stress state of crimped pultruded composite rods subjected to traction has been investigated analytically using the linear theory of elasticity of anisotropic body and the superposition principle. The theoretical solution is able to reproduce the finite element analysis results and clarify the relation between the stress state and the boundary stresses. It can be appreciated from the theoretical solution that a longitudinal compressive stress at the edge of the crimping zone is generated by the boundary shear stress induced by the flow of metal end-fitting. Thus it can be deduced that the stress concentration at the edge of crimping zone could be mitigated through appropriately increasing the extent of the flow of the metal end-fitting away from the middle of the crimping zone. Our research shows that a radial tensile stress existing at the edge of the crimping zone is corresponding to the area of the rod that axial splitting is taken place. Comparison between analytical and numerical results shows the analytical results are in good agreement with the numerical ones except for stress distribution at the edge of the loading zone. The detailed study on stress state at the edge of the crimping zone provides better understanding of the failure mechanism, the improvement possibilities on the crimping technique and the monitoring of the structural health of the composite rod.

An efficient visible fluorescent optical fiber embedded with silver nanoclusters (Ag-NCs) having
size 1 nm, uniformly distributed in alumina-silica composite core glass, is reported. Fibers are
fabricated in a repetitive controlled way through modified chemical vapour deposition process
associated with solution doping technique. Fibers are drawn from the transparent preforms by conventional
fiber drawing process. Structural characteristics of the doped fibers are studied using
transmission electron microscopy and electron probe micro analysis. The oxidation state of Ag
within Ag-NCs is investigated by X-ray photo electron spectroscopy. The observed significant fluorescence
of the metal clusters in fabricated fibers is correlated with electronic model. The experimentally
observed size dependent absorption of the metal clusters in fabricated fibers is explained
with the help of reported results calculated by ab-initio density functional theory. These optical
fibers may open up an opportunity of realizing tunable wavelength fiber laser without the help of
rare earth elements.

We report on the use of a cost-effective erbium-doped based optical preamplifier in a single-ended distributed fiber-optic sensor to improve receiver sensitivity and hence measurement range. The improved accuracy of spontaneous Brillouin measurements was demonstrated in a 23km sensor and was limited by amplified spontaneous emission from the preamplifier, which was verified theoretically. Reduction of amplified spontaneous emission was achieved with a 0.37nm in-fiber Bragg grating. A signal-to-noise improvement of 17dB was achieved and supported by theory, which translates to approximately 40km range improvement for a single-mode sensing fiber having losses of 0.2dB/km at 1550nm.

In the recent decades, sensors have affected on our life in various fields, including research activities, standardization procedures, and industrial investments. Various types of sensors (e.g., pressure, temperature, and humidity) can be used in Wireless Sensor Networks (WSNs) to design and implement some of the important applications, such as environmental monitoring, healthcare systems, and military issues. WSNs consist of the low-power, large-scale, and low-cost sensor nodes. The nodes measure phenomena data (e.g., smoke density) to transmit the measured data to a center (e.g., sink or base station). Routing, security, and fault tolerance are some of the crucial challenges in sensor networks. This paper describes various physical features and key usages of the popular sensors. Furthermore, three WSNs applications in monitoring, healthcare, and military are considered subsequently. Since sensor localization and data mining are two important topics in WSNs, their categories and characteristics are addressed too. Evaluation results show the performance of sensor networks compared to radio-frequency identification (RFID) in terms of utilization, purpose, components, mobility, power supply, programmability, and deployment. Besides, some of the WSNs simulators are compared to each other in terms of computation time and memory usage.

—Raman Distributed Temperature Sensors (RDTSs) offer exceptional advantages to monitor the envisioned French deep geological repository for nuclear wastes, called Cigéo. Both-ray and hydrogen release from nuclear wastes can strongly affect the temperature measurements made with RDTS. We present experimental studies on how the performances of RDTS evolve in harsh environments like those associated with-rays or combined radiations and release. The response of two standard and one radiation tolerant multimode fibers (MMFs) are investigated. In all fibers the differential induced attenuation between Stokes and anti-Stokes signal, causes a temperature errors, up to with standard multimode fibers (100 m) irradiated at 10 MGy dose. This degradation mechanism that is more detrimental than the radiation induced attenuation (RIA) limiting only the sensing range. The attenuation in the [800-1600 nm] spectral range at room temperature is explored for the three fibers-irradiated and/or hydrogen loaded to understand the origin of the differential RIA. We show that by adapting the characteristics of the used fiber for the sensing, we could limit its degradation but that additional hardening by system procedure is necessary to correct the T error in view of the integration of our RDTS technology in Cigéo. The current version of our correction technique allows today to limit the temperature error to for 10 MGy irradiated samples.

—We report on the development of a multiplexed sensor array of fiber Bragg gratings (FBGs), inscribed using a femtosecond laser, and its demonstration as a quasi-distributed sensor to capture the mode shapes, through surface displacement sampling, of a free-free vibrating beam. Our method is based on a plane-by-plane (Pl-b-Pl) inscription approach, whereby a 2D index change is written across the fiber core, controlling the width and depth of the modified region. This allows for the fast inscription of multiple wavelength FBGs in coated optical fibers, with the advantage of less stringent alignment requirements. The FBGs are multiplexed in the wavelength domain using a high-speed demodulator, using a fast, custom-made computational algorithm. We recover rapid and single-step wavelength-and time-dependent displacement information, extracting the first two mode shapes of a vibrating beam and their respective degrees of freedom resonance frequencies in < 0.4s.

Fiber Optics Reflectance Sensor based on CR-39 was employed to monitor online low level alpha radiations emitted from 241 Am. Change in reflectance was found to be inversely related to roughness of the film. The sensitivity of the detector far exceeds the sensitivity obtained by measuring the track density. Experimentally measured track density matched with Monte Carlo GEANT4 simulation results.