Plastic optical fiber

Advanced modulation formats can enable >40 Gb/s data rates in waveguide-based optical interconnects without the need for high-specification optoelectronic components. Record 56Gb/s PAM-4 data transmission is demonstrated over a 1 m-long multimode polymer waveguide.

Hard polymer clad fiber Plastic optical fiber Metal-coated optical fiber a b s t r a c t Fiber optic sensing technology is used extensively in several engineering fields, including smart structures, health and usage monitoring, non-destructive testing, minimum invasive sensing, safety monitoring, and other advanced measurement fields. A general optical fiber consists of a core, cladding, and coating layers. Many sensing principles require that the cladding or coating layer should be removed or modified. In addition, since different sensing systems are needed for different types of optical fibers, it is very important to find and sort out the suitable cladding or coating removal method for a particular fiber. This study focuses on finding the cladding and coating stripping methods for four recent specialty optical fibers, namely: hard polymer-clad fiber, graded-index plastic optical fiber, copper/carbon-coated optical fiber, and aluminum-coated optical fiber. Several methods, including novel laser stripping and conventional chemical and mechanical stripping, were tried to determine the most suitable and efficient technique. Microscopic investigation of the fiber surfaces was used to visually evaluate the mechanical reliability. Optical time domain reflectometric signals of the successful removal cases were investigated to further examine the optical reliability. Based on our results, we describe and summarize the successful and unsuccessful methods.

This paper describes a new optical link system which consists of a metal optical bench, a module printed circuit board, a driver/receiver integrated circuit, a vertical-cavity surface-emitting laser/photo diode (VCSEL/PD) array, and an optical link block with plastic optical fibers for reducing electromagnetic interference (EMI) noise. For the optical interconnection between the light-sources and detectors, an optical wiring method whose distinctive features include the absence of EMI noise and easy assembly is proposed. The results clearly demonstrate that the use of an optical wiring method can provide robust, cost-effective assembly and easy-repair. We successfully achieved a 4.5 Gb/s data transmission rate without EMI problems.

Optical interconnects have attracted significant research interest for use in short-reach board-level optical communication links in supercomputers and data centers. Multimode polymer waveguides in particular constitute an attractive technology for on-board optical interconnects, as they provide high bandwidth, offer relaxed alignment tolerances, and can be cost-effectively integrated onto standard printed circuit boards (PCBs). However, the continuing improvements in bandwidth performance of optical sources make it important to investigate approaches to develop high-bandwidth polymer waveguides. In this paper, we present dispersion studies on a graded-index (GI) waveguide in siloxane materials designed to deliver high bandwidth over a range of launch conditions. Bandwidth-length products of >70 and ∼65 GHz×m are observed using a 50/125 μm multimode fibre (MMF) launch for input offsets of ±10 μm without and with the use of a mode mixer (MM), respectively; and enhanced values of >100 GHz×m are found under a 10× microscope objective launch for input offsets of ∼18 × 20 μm 2. The large range of offsets is within the –1 dB alignment tolerances. A theoretical model is developed using the measured refractive index profile of the waveguide, and general agreement is found with experimental bandwidth measurements. The reported results clearly demonstrate the potential of this technology for use in high-speed board-level optical links, and indicate that data transmission of 100 Gb/s over a multimode polymer waveguide is feasible with appropriate refractive index engineering.

The modeling of a side-polished plastic optical fiber as a sensor of two distinct physical parameters is presented. A comprehensive analytical study is performed using a geometric optic approach. Different details are taken into account, such as the geometric description of the sensor, the intensity profile of the emitter, and the possibility of a multireflection for a light ray at the sensitive area. The good agreement between the experimental and theoretical results validates the developed analytical model.

This paper proposes the use of imperfected graded-index plastic optical fibers as sensing elements in deformation sensors. Use of a graded-index fiber instead of a step-index fiber for bending measurements resulted in an increase in sensitivity. Multi-loop configuration led to an even greater increase in sensitivity, reaching saturation after 15 half-loops. Imperfections implemented on the fiber further increased the sensitivity, although any variation of more than three imperfections, either all on one loop or each on separate loops, brought the sensitivity of the sensor to saturation. The maximal resolution obtained within a 25 mm radius range was 20 mm, with an even greater resolution at smaller ranges. These promising initial results indicate that sensors based on imperfected graded-index plastic optical fibers merit further study. r

In this work an innovative and low cost surface plasmon resonance (SPR) biosensor, based on the utilization of plastic optical fibers (POF), is presented and experimentally tested for the diagnosis and/or follow-up of celiac disease. In particular, the POF-based sensor was used to monitor the formation of the transglutaminase/anti-transglutaminase antibodies formation, a new hallmark for the diagnosis of celiac disease. In particular, on the gold layer surface of the POF sensor, the guinea pig transglutaminase was immobilized. The ability of the POF-sensor to detect the binding of anti-transglutaminase antibodies to the immobilized transglutaminase was studied.

Novel plastic optical fibers (POF) based on polymethylmethacrylate, PMMA, doped with luminescent conjugated polymers and oligomers were fabricated. Our innovative approach is based on the chemical binding between the PMMA matrix and the dopant material as an alternative to the blending approach (mixture) of PMMA and the active material. We aimed at controlling load and dispersi on of the luminescent polymer in the PMMA matrix, which are crucial for the optimisation of these optical media, while reducing the possibility of dopant segregation during the fiber drawing. Stimulated emission and optical switching inside th e fiber were observed in some of the new materials, indicating t hat they can represent possible routes to plastic optical media, namely POFs, exhibiting gain and ultrafast switching.

We investigate 40-Gb/s cost-efficient transmitter for access and metro networks. This 40-Gb/s transmitter comprises a standard directly modulated distributed-feedback (DFB) laser and a subsequent optical filter. Large dispersion tolerance of this transmitter is realized by chirp control through the phase correlation between adjacent bits for the destructive interference in order to erase the power of "0" bits while enhancing the extinction ratio. The chirp model of the DFB laser and the optimum parameters of the optical filter have been numerically analyzed. The chirp-managed 42.8-Gb/s transmission over 20-km standard single mode fiber (SSMF or SMF-28) without dispersion compensation and a centralized lightwave WDM-PON system are experimentally demonstrated. We have also realized the transmission over 100-m graded index plastic optical fiber (GI-POF). Moreover, the application in the metro network over 240-km SSMF or SMF-28 has also been investigated in this paper.

We investigate 40-Gb/s cost-efficient transmitter for access and metro networks. This 40-Gb/s transmitter comprises a standard directly modulated distributed-feedback (DFB) laser and a subsequent optical filter. Large dispersion tolerance of this transmitter is realized by chirp control through the phase correlation between adjacent bits for the destructive interference in order to erase the power of "0" bits while enhancing the extinction ratio. The chirp model of the DFB laser and the optimum parameters of the optical filter have been numerically analyzed. The chirp-managed 42.8-Gb/s transmission over 20-km standard single mode fiber (SSMF or SMF-28) without dispersion compensation and a centralized lightwave WDM-PON system are experimentally demonstrated. We have also realized the transmission over 100-m graded index plastic optical fiber (GI-POF). Moreover, the application in the metro network over 240-km SSMF or SMF-28 has also been investigated in this paper.

We fabricated resonant-cavity light-emitting diodes (LEDs) emitting at 650 nm. Compressively strained GaInP quantum wells were used as an active layer embedded between AlGaAs-AlAs Bragg mirrors. The Bragg mirrors formed a one-wavelength optical resonator. Two devices with different light-emitting areas were compared: 1) a large area chip (300 m 300 m) with a conventional LED contact and 2) a small area chip with an 80-m light opening with an annular contact. Large devices are more suitable for high output power, whereas the smaller devices might be useful for data transmission e.g., via plastic optical fibers. For epoxy-encapsulated large area devices, we achieved a maximum wall-plug efficiency of 10.2% and maximum output power of 12.2 mW at 100 mA. The small area LEDs yielded 2.9 mW at 20 mA and a maximum wall-plug efficiency of 9.5%.

ÐThe basic electrical equivalent circuit of an AlGaInP based 650 nm ring-LED proposed for plastic-optical ®ber data-links is derived. The LED's modulation bandwidth is found to be 65 MHz at a link average driving bias current of 35 mA. The LED's modulation response is measured and shows an open-eye diagram for 156 Mbps non-return-to-zero (NRZ), pseudo-random signals with and without a peaking circuit, respectively.

This Engineering and Laboratory Note describes a simple, fast, cost-effective, and practical splicing technique for poly-methyl-methacrylate (PMMA) plastic optical fibers. We believe this technique can be useful for home networks , laboratory research, and educational uses. It employs a widely available, low-cost transparent adhesive combined with a suitable alignment sleeve. The fiber tips did not need to be cleaned or polished, and the polyethylene jacket did not need to be removed. The alignment between the cleaved fibers was performed by means of the jacket. Low insertion losses were measured for the main PMMA-based fiber types.

In this paper we propose the application of plastic optical fiber to monitor the concrete curing process. The proposed method is based in the scattering of the propagated optical signal in grooves imposed to the fiber. By monitoring the intensity of the transmitted light signal, along time, we can determine the cement setting rate along all the curing period. The obtained results show that the system has enough sensitivity to analyze a curing period of 28days, where the received optical power is 5% of the initial value.

A cumulative sensor for in situ monitoring of H 2 S vapors in museum showcases based on plastic optical fiber (POF) has been developed. H 2 S is responsible for the tarnishing of silver artifacts, so monitoring their total exposure over time to sulfide rich atmospheres can help in choosing the correct display procedure and, consequently, lead to improvements in their conservation.

We experimentally demonstrate a bit-rate of 47.4 Gb/s over 100 m of perfluorinated multimode graded-index plastic optical fiber (GI-POF) by exploiting discrete multitone (DMT) modulation with rate-adaptive bit-loading. The maximum achieved aggregate bit rate is 51.8 Gb/s including DMT transmission overhead (cyclic prefix and preambles) and the standard of 7% of forward-error-correction (FEC) overhead. This is achieved over an intensity-modulated direct-detection (IM-DD) link using a directly-modulated DFB laser (1300-nm) and a multimode fiber-coupled photodetector with a large diameter of 25-m. The bandwidth requirement is only 12 GHz due to the use of spectral-efficient modulation formats of up to 64-QAM.

We report on different optical coupling concepts between resonant-cavity light-emitting diodes and plastic optical fiber for the automotive according to the Multimedia Oriented Systems Transport standard. We present five different candidate optical coupling schemes. Two coupling schemes were investigated in depth regarding manufacturing and assembly tolerances using a Monte Carlo simulation method: a system using a ball lens and another made by clear molding. We select the best suited system according to manufacturing and assembly capabilities as well as its suitability for automotive applications.

Polymer Optical Fiber (POF) can be and are being used in various field of application, especially for short haul communication application due to the high-speed data transmission, reach up to 100 meter distance data communication and of course have higher bandwidth. Hence, POF here can be seen as one of the best solution for home networking application. Customer-made multimode optical 1x3 fused-taper-twisted POF couplers have been fabricated by a perform technique. There several systems available on the market, which can be split or combine some optical signals to be transmitted into some different channels, which are all afflicted with certain disadvantages. But all these solutions have one main disadvantage; they are all too expensive for most of the applications mentioned above. So the goal of this study is to develop an economical coupler for home networking application over POF. Characterization of the coupler was reported. Red LED with a 650 nm wavelength has been injected into the coupler for the purpose of characterization testing to analyze the level of power efficiency of the coupler. Final analysis shows that efficiency of coupler output able to reach up to 30%. The device performance can be improved gradually through experience and practice. Main point here is the fabrication process is simple, easy and suitable to be used for household.

Design and characterization of a pH optical fiber sensor with a pH sensitive dye is described in this paper. TEOS (Tetra-ethyl-Orto-Silicate) was used to dope a plastic optical fiber, which will be used as the optical probe (OPTRODE). The sensor is prepared by fixing the doped plastic fiber on a fused ortosilica block surface with blue bromophenol. The fiber surface charged with silica modified the refractive index, which plays an important roll on the fiber, modifies the conditions of light propagation into the plastic optical fiber. The fiber transmittance is used to measure the pH of a solution or a fluid in a range between 4 and 7; such signal is captured by a photodetector and processed with a LabView program. The advantage of this system is that, 2cm of doped fiber are enough to measure the pH of a fluid in real time. The time response of the sensor reported in the present study is approximately 10s.

Abstruct-A high-brightness light-emitting diode (LED) is fabricated using the AlGaInP based quaternary double heterostructure. The ring type electrode is used in the top contact in order to spread the current efficiently and also to enhance the coupling efficiency with the fiber. The fabricated LED has a light output as high as 1.7 mW at the bias current of 100 mA. The farfield radiation divergences are found to be approximately 10" and 70" for the LED's, with and without molding. These LED's offer coupling efficiency as high as 70% and 35%, with the step index (SI) plastic optical fiber (POF) after using the molded and hybrid ball lens, respectively. The increases of the coupling efficiency are due to the use of the ring-shaped top electrode, concentrating the emission mostly at the center.

A system for measuring liquid level in multiple tanks using optical fibe technology has been developed. Oil fiel service industry or any sector requiring liquid level measurements in flammabl atmospheres can be benefite from this intrinsically safe technology. The device used a single lens for the emitting and receiving fibe and it is based on amplitude variations as a function of the liquid distance and not in time of fligh or phase detection. Being the firs fiber-opti liquid level sensor with those characteristics for long ranges (>200 cm). A simple model to describe their behavior has been derived and tested on two prototypes. A Monte-Carlo method is used to fi the experimental data and obtain the model parameters. High accuracy between experimental data and fitte curve is obtained. The prototypes have a good linearity, better than 1.5% FS (full scale). Sensor heads are made of plastic optical fiber (POF) that are easy to handle, fl xible and economical. They are excited by 650 nm lasers, housed in ST-connectors to obtain compact and rough prototypes. Optical multiplexing is used to increase the measuring safety area. Frequency division multiplexing is used to address each sensor head. A discussion about the influenc of tilts and aberrations is also included.

In the scenario of world energy crisis, building energy efficiency has become a mainstream research focus; since buildings take up a large share of the world energy consumption. Lighting plays an integral part in the building’s operationality through providing indoor visual comfort; and the much-needed daylight harnessing in building structures can be achieved through various strategies. This paper aims to evaluate the amount of plastic optical fiber (POF) required for achieving optimum indoor illumination through light transport and study the advantage of two dimensional solar tracking and light concentration on indoor daylight enhancement through POF as a trade-off for the amount of POF required in a static system. Illumination attained inside a representative closed chamber due to light transported by POF via various mechanisms was experimentally compared with outdoor direct illumination and the amount of POF required for achieving comfortable indoor illumination was calculated for a proposed system involving tracking and light concentration. A microcontroller based dual-axis solar tracker was designed for tracking sunlight on the POF collector node every 10 seconds and opaque internally reflective plastic containers acted like sample rooms in a building. Calculations for the representative day normalized for the flooring area in an office building showed a promising payback period of around 5 years through partial replacement of electric lighting. Additionally, reduction in heat conduction through window glazing further reduces the cooling costs.

Daylighting has a very effective role in reducing power consumption and improving indoor environments in office buildings. Previously, it was not under consideration as a major source of renewable energy due to poor reliability in the design. Optical fiber as a transmission medium in the daylighting system demands uniform distribution of light to solve cost, heat, and efficiency issues. Therefore, this study focuses on the uniform distribution of sunlight through the fiber bundle and to the interior of the building. To this end, two efficient approaches for the fiber-based daylighting system are presented. The first approach consists of a parabolic mirror, and the second approach contains a Fresnel lens. Sunlight is captured, guided, and distributed through the concentrator, optical fibers, and lenses, respectively. At the capturing stage, uniform illumination solves the heat problem, which has critical importance in making the system cost-effective by introducing plastic optical fibers. The efficiency of the system is increased by collimated light, which helps to insert maximum light into the optical fibers. Furthermore, we find that the hybrid system of combining sunlight and light emitting diode light gives better illumination levels than that of traditional lighting systems. Simulation and experimental results have shown that the efficiency of the system is better than previous fiber-based daylighting systems.

This study shows an easy and effective design of an optical fiber communication system, which demonstrates EDFA's ideal position in the whole system. In recent years, erbium-doped fiber amplifiers (EDFAs) have been more attentive with the development of high-speed and long-distance data transmission systems. In our research, EDFA's forward pump capacity is maintained at 100mW, and our three configurations modify and analyze the location of EDFA. First configuration is meant to place EDFA before optical fiber in the entire system. The second arrangement has been intended such that EDFA will precede optical fiber. EDFA is inserted in the third configuration between the optical fiber length. For the three setups, the BER, Q factor and output power level were observed, with the setup one having minimal BER, setup two with the greatest power, and setup three with the maximum Q factor. This paper discusses the causes behind these results and designers may construct an optical fiber communication system in the most efficient and reliable fashion by taking those results into consideration. The simulation was performed in Opti-System software.

We prepare optrodes of fiber optic plastic with sol-gel technique. Suitable concentration of carbone nanotubes (CNTs), phenol red, bromophenol blue and cresol red, design optrodes with fiber optic plastic. The surface charge of silica and the refractive index, which play an important roll on the fiber, modifies the conditions of light propagation into the plastic optical fiber. We use the transmittance to measure the pH of a solution or fluid in a range between 3 and 9.

We investigate 40-Gb/s cost-efficient transmitter for access and metro networks. This 40-Gb/s transmitter comprises a standard directly modulated distributed-feedback (DFB) laser and a subsequent optical filter. Large dispersion tolerance of this transmitter is realized by chirp control through the phase correlation between adjacent bits for the destructive interference in order to erase the power of "0" bits while enhancing the extinction ratio. The chirp model of the DFB laser and the optimum parameters of the optical filter have been numerically analyzed. The chirp-managed 42.8-Gb/s transmission over 20-km standard single mode fiber (SSMF or SMF-28) without dispersion compensation and a centralized lightwave WDM-PON system are experimentally demonstrated. We have also realized the transmission over 100-m graded index plastic optical fiber (GI-POF). Moreover, the application in the metro network over 240-km SSMF or SMF-28 has also been investigated in this paper.

A refractometric sensor that uses the transition region of a U-bent Plastic Optical Fiber (POF) when it is polished laterally is presented. By polishing a lateral segment of the fiber, a part of the plastic optical fiber core is removed and an elliptical surface is formed on the bend. It is found that that the polishing with an angle equals to the critical angle of a straight optical fiber the sensitivity of this transducer structure is enhanced. Then, the incident light is totally reflected and the transition losses decrease locally. In addition, the sensitivity increases compared to the polishing in the region of bending losses. The proposed transducer is successfully checked with experimental measurements and different kinds of liquids. Potential applications are suggested.

The use of standard 1-mm core-diameter step-index plastic optical fiber (SI-POF) has so far been mainly limited to distances of up to 100 m and bit-rates in the order of 100 Mbit/s. By use of digital signal processing, transmission performance of such optical links can be improved. Among the different technical solutions proposed, a promising one is based on the use of discrete multitone (DMT) modulation, directly applied to intensity-modulated, direct detection (IM/DD) SI-POF links. This paper presents an overview of DMT over SI-POF and demonstrates how DMT can be used to improve transmission rate in such IM/DD systems. The achievable capacity of an SI-POF channel is first analyzed theoretically and then validated by experimental results. Additionally, first experimental demonstrations of a real-time DMT over SI-POF system are presented and discussed.

A simple tapered plastic multimode (PMM) fiber optic sensor is proposed and demonstrated for continuous monitoring of salinity based on different concentration of sodium chloride (NaCl) in de-ionized water. The working mechanism of such device is based on the observed increment in the transmission of the sensor that is immersed in sodium chloride solution of higher concentration which also reflects an increase in its refractive index. The tapered PMM fiber is fabricated using heat-pulling method to achieve a waist diameter and a length of 0.187 mm and 5 mm, respectively. As the solution concentration varies from 0% to 12%, the output voltage of the sensor increases linearly from 0.109 mV to 1.142 mV with a sensitivity of 0.0024 mV/% and a linearity of more than 98%. The main advantages of this sensor are the feasibility of using PMM fiber which makes the sensor tougher, easier to fabricate and handle. © 2011 Elsevier B.V.

http://ac.els-cdn.com/S0924424711005383/1-s2.0-S0924424711005383-main.pdf?_tid=9d4acc48-cb6b-11e3-bedc-00000aab0f26&acdnat=1398315061_0f39efa633dad0adad0693e6e9386323 
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A 1 × 2 Plastic optical fiber (POF) Y-coupler has been designed and fabricated using a simple acrylic (PMMA) mold insert. The device is composed of three segments: an input POF fiber, an intermediate hollow taper waveguide and output POF fibers. The acrylic mold insert has been fabricated using EGX-400 desktop engraver machine with a spindle speed of 15 K rpm and feed rate of 5 mm/sec. The engraved regions which is a form of U-groove allows 1 mm core step index PMMA POF fibers to be slotted into the mold insert. The short POF fibers at the input and output ends are slotted inside the mold insert before the interfaces of the taper waveguide. A top acrylic plate is then placed on top of the fabricated device and sealed. The final device has been tested for both splitter and combiner operations for an effective power of 1 mW. The device has an insertion loss of 10.48 dB. In the splitter operation, the device has a splitting ratio of 52 : 48. In the combiner operation, the combined power is −11.15 dB for input power of −11.90 dB and −12.05 dB.

Problem statement: Multimode fiber cables can conduct many light rays and can operate free of disruption and with a greater bandwidth than a wireless connection. However, due to a slight variation in the speed of the light rays through the multimode fiber, a signal transmitted by all of these rays becomes spread out. Consequently, the signals become broader and therefore fewer signals fit in the fiber, limiting the transmission capacity. These demands grow almost daily. Hence new ways of splitting methods must be found to satisfy all application demands, especially related to automotive application. Approach: Home-made 1×12 optical splitter based on polymer optical fiber material base is one of the most innovative technologies on optical component which can be applied on some useful application. A perform technique had been used to fabricate kind of splitter. In order to develop such an efficient optical device which can be integrated into the body of automotive field, research with a good specification-oriented study tent to be conduct and it must be passed through a well-planned fabrication technique together with a proper characterization process. Multimode Step-Index Polymer Optical Fiber (SI-POF) type made of polymethyl methacrylate (PMMA) with Ø core = 1 mm and NA: 0.50 fully utilized in this research, as PMMA is one of the most commonly used optical materials. This material has been chosen as a base of splitter body in a fused-taper-twisted shape, produced by a unique fabrication stages. PMMA-POF can easily be used near it operating temperature between -40°C to +115°C. Results: By injecting 650 nm wavelength of red LED, characterization process start plays an important role in investigating level of efficiency of the device. Some parameters, such as optical output power and power losses on the devices were observed. Although the maximum output power efficiency of the splitter is about 40% but it can be improved gradually through experience and practice. Conclusion: The fabrication process is simple, easy and suitable to be used by household. Moreover, the users can determine the size of the fabricated device themselves. The POF-based optical 1×12 splitter had been suggested to be applied into automobile application to overcome blind spot area tracking problem as a one of low-cost solution in the future and also in home networking to avoid the bottleneck occurs between ONU and electronic appliances, resulting increase the speedy of data communication.

The use of plastic optical fibers (POFs), curved at the sensing point and coated with cobalt chloride (CoCl 2 ) and gelatin as the overlay material, for relative humidity sensing is demonstrated in this paper. The fiber-core diameter and bending radius of the sensing point affects the sensitivity of the sensor to a great extent.

The performance of Space-Time Block Codes combined with Discrete MultiTone modulation applied in a Large Core Step-Index POF link is examined theoretically. A comparative study is performed considering several schemes that employ multiple transmitters/receivers and a fiber span of 100 m. The performance enhancement of the higher diversity order configurations is revealed by application of a Margin Adaptive Bit Loading technique that employs Chow's algorithm. Simulations results of the above schemes, in terms of Bit Error Rate as a function of the received Signal to Noise Ratio, are provided. An improvement of more than 6 dB for the required electrical SNR is observed for a 3 × 1 configuration, in order to achieve a 10 3 BER value, as compared to a conventional Single Input Single output scheme.

Problem statement: Multimode fiber cables can conduct many light rays and can operate free of disruption and with a greater bandwidth than a wireless connection. However, due to a slight variation in the speed of the light rays through the multimode fiber, a signal transmitted by all of these rays becomes spread out. Consequently, the signals become broader and therefore fewer signals fit in the fiber, limiting the transmission capacity. These demands grow almost daily. Hence new ways of splitting methods must be found to satisfy all application demands, especially related to automotive application. Approach: Home-made 1×12 optical splitter based on polymer optical fiber material base is one of the most innovative technologies on optical component which can be applied on some useful application. A perform technique had been used to fabricate kind of splitter. In order to develop such an efficient optical device which can be integrated into the body of automotive field, research with a good specification-oriented study tent to be conduct and it must be passed through a well-planned fabrication technique together with a proper characterization process. Multimode Step-Index Polymer Optical Fiber (SI-POF) type made of polymethyl methacrylate (PMMA) with Ø core = 1 mm and NA: 0.50 fully utilized in this research, as PMMA is one of the most commonly used optical materials. This material has been chosen as a base of splitter body in a fused-taper-twisted shape, produced by a unique fabrication stages. PMMA-POF can easily be used near it operating temperature between -40°C to +115°C. Results: By injecting 650 nm wavelength of red LED, characterization process start plays an important role in investigating level of efficiency of the device. Some parameters, such as optical output power and power losses on the devices were observed. Although the maximum output power efficiency of the splitter is about 40% but it can be improved gradually through experience and practice. Conclusion: The fabrication process is simple, easy and suitable to be used by household. Moreover, the users can determine the size of the fabricated device themselves. The POF-based optical 1×12 splitter had been suggested to be applied into automobile application to overcome blind spot area tracking problem as a one of low-cost solution in the future and also in home networking to avoid the bottleneck occurs between ONU and electronic appliances, resulting increase the speedy of data communication.

Recent activity to achieve multi-gigabit transmission over 1 mm core diameter graded-index and step-index plastic optical fibers for distances up to 50 meters is reported in this paper. By employing a simple intensity-modulated direct-detection system with pulse amplitude or digital multi-tone modulation techniques, low-cost transceivers and easy to install large-core POFs, it is demonstrated that multi-gigabit transmission up to 10 Gbit/s over 1-mm core diameter POF infrastructure is feasible. The results presented in this paper were obtained in the EU FP7 POF-PLUS project, which focused on applications in different scenarios, such as in next-generation in-building residential networks and in datacom applications.

We investigate 40-Gb/s cost-efficient transmitter for access and metro networks. This 40-Gb/s transmitter comprises a standard directly modulated distributed-feedback (DFB) laser and a subsequent optical filter. Large dispersion tolerance of this transmitter is realized by chirp control through the phase correlation between adjacent bits for the destructive interference in order to erase the power of "0" bits while enhancing the extinction ratio. The chirp model of the DFB laser and the optimum parameters of the optical filter have been numerically analyzed. The chirp-managed 42.8-Gb/s transmission over 20-km standard single mode fiber (SSMF or SMF-28) without dispersion compensation and a centralized lightwave WDM-PON system are experimentally demonstrated. We have also realized the transmission over 100-m graded index plastic optical fiber (GI-POF). Moreover, the application in the metro network over 240-km SSMF or SMF-28 has also been investigated in this paper.

We demonstrated a new-designed plastic-optical-fiber-bundle (POFB) coupler array for dynamic monitoring and end-point detection of the photoresist development process. A better optical collecting efficiency is achieved by using a normal illumination/detection scheme and a POFB coupler with larger cross section. Time-resolved dissolution rate can be obtained by synchronous calculation of the reflected optical interference data with deviation of less than 1.5%. Experiment on in-situ mapping of transient thickness variation of photoresist film during development by using two-dimensional POFB coupler array is also reported. The POFB-based coupler exhibits relatively low coupling and insertion loss at visible light wavelength as compared with the silica-fiber-based one. The system is compatible for real-time/multi-port measurements of micro-lithographic and dielectric etching processes.

A 1 × 2 Plastic optical fiber (POF) Y-coupler has been designed and fabricated using a simple acrylic (PMMA) mold insert. The device is composed of three segments: an input POF fiber, an intermediate hollow taper waveguide and output POF fibers. The acrylic mold insert has been fabricated using EGX-400 desktop engraver machine with a spindle speed of 15 K rpm and feed rate of 5 mm/sec. The engraved regions which is a form of U-groove allows 1 mm core step index PMMA POF fibers to be slotted into the mold insert. The short POF fibers at the input and output ends are slotted inside the mold insert before the interfaces of the taper waveguide. A top acrylic plate is then placed on top of the fabricated device and sealed. The final device has been tested for both splitter and combiner operations for an effective power of 1 mW. The device has an insertion loss of 10.48 dB. In the splitter operation, the device has a splitting ratio of 52 : 48. In the combiner operation, the combined power is −11.15 dB for input power of −11.90 dB and −12.05 dB.

An optical code generating device using plastic optical fiber (POF) coupler for a portable optical access card system is presented. The code generating device has been constructed using asymmetric hollow POF coupler design. The device provides a unique series of output light intensities which are successively used as an optical code. Ray tracing models of various coupler designs showed a linear relationship between the tap-off ratio (TOFR) and the waveguide tap width. The asymmetric POF coupler has been fabricated on metal-based materials using machining technique. The results for the simulated and fabricated metal-based 1Â2 asymmetric couplers show the same linear characteristics between the TOFR and the tap width. The simulated devices show a TOFR variation from 18.6 to 49.9% whereas the TOFR for the fabricated metal-based devices varies from 10.7 to 47.7%, for a tap width of 500 mm to 1 mm. The insertion loss for the 1Â2 asymmetric coupler at the tap line varies from 12.7 to 21.2 dB whereas for the bus line, the average insertion loss is about 12 dB.

The use of plastic optical fibers (POFs), curved at the sensing point and coated with cobalt chloride (CoCl 2) and gelatin as the overlay material, for relative humidity sensing is demonstrated in this paper. The fiber-core diameter and bending radius of the sensing point affects the sensitivity of the sensor to a great extent.

Low-loss and high-bandwidth (>47 GHz×m) multimode polymer waveguide crossings (<0.02 dB/crossing) and bends (<1dB) are demonstrated. The performance of passive optical backplanes comprising such components is also optimised using refractive-index engineering and launch conditioning.

We report enhanced graded-index multimode polymer waveguides with >70GHz×m for MMF launch and >200GHz×m for restricted launch, indicating the capability of on-board waveguide transmission of >100 Gb/s. Simulations using the measured refractive index profile agree well with the experiments.

The paper analyzes the performance of a dual-wavelength technique devised to compensate power fluctuations in intensity-modulated plastic optical fiber sensors, which were specifically conceived for the measurement of displacements in industrial and civil applications. These sensors retrieve the displacement from the variation of the attenuation along the light path and use two signals at different wavelengths to compensate for the effects of parasitic quantities, such as temperature and strains along the fiber. The theoretical behavior of the compensation technique is presented, and the results of experiments carried out with different combinations of signal wavelengths and plastic fibers are reported. The experimental setup has proved that, by proper choice of the compensation signal wavelength, it is possible to monitor displacements in the range (0 to 10) mm, even for low received power and under severe perturbation conditions, thus significantly improving the long-term stability of the sensors.

InGaP/AlGaInP 660-nm resonant-cavity light-emitting diodes (RCLEDs) with stable temperature characteristics have been achieved by extending the resonant cavity length from one optical wavelength (1 ) to three optical wavelengths (3 ) and tripling the number of quantum wells. When the operation temperature increases from 25 C to 95 C, the degree of power variation at 20 mA is reduced from 2.1 dB to 0.6 dB for the conventional 1-cavity RCLEDs and 3-cavity RCLEDs, respectively. In order to interpret the temperature-dependent experimental results, advanced device simulation is applied to model the RCLEDs with different cavity designs. According to the numerical simulation results, we deduce that the stable temperature-dependent output performance should originate from the reduction of electron leakage current and thermally enhanced hole transport for the 3-cavity AlGaInP RCLEDs.