We applied an ultrasonic welding method for the bonding of plastic fibers, and obtained many types of optical star couplers for optical communication systems. It enables the manufacturing of optical components with low loss without damaging the clad layer except for the welding surface. Therefore, they have some merits, such as low loss, small size, light weight, and low cost. The 4-ports (2 X 2) star coupler of 1000 micrometers diam APF has 0.7 dB excess loss at most, and the welding length is 20 mm.
High heat resistant optical fibers (POFs) have been developed for various automotive applications. Plastic chips with POF light guide have been used in place of a clearance monitor lamp. POF cords and cables have been used in the car-audio system, car-navigation system, and other data communication systems. This paper describes the structures, properties, and reliabilities of POFs for these applications.
In past years, plastic optical fibers (POF) have gained more and more interest because of features like low-cost, easy handling, and good flexibility even at large diameters. Therefore, these fibers are considered to be suitable for short-haul data transmission applications in computer links or in automobiles. However, the breakthrough of POF is prohibited by two major disadvantages, namely the relatively high loss of about 200 dB/km and the low heat resistance of 80 - 90 degree(s)C, which is not sufficient for the automotive area. In distributed networks even for short distance transmission, improvements in the optical loss are very essential.
Instrumentation and general methodology to conduct time domain dispersion measurements on polymer optical fiber are described. The equipment and analysis procedures for performing these measurements at 670 nm are presented together with experimental results on PMMA core fiber. Measured bandwidths are very dependent on launching conditions and may be substantially greater than those predicted for ideal step-index fibers. Effects such as mode dependent attenuation and mode coupling which
The information explosion that occurred in the 1980s led to the widespread introduction of personal computers to the office, laboratory, and factory environments. The need to share information and resources amongst workstations demanded a networking solution, specifically a local area network (LAN). Since that time many media have been developed for use in LANs, each meeting a specific user demand. Glass fiber was developed for use in long distance, high bandwidth applications, but the high cost of hardware and installation has daunted users. Twisted pair was developed as a low cost alternative medium for use in shorter distance applications. However, as computer applications have become more graphics intensive, LANs have been required to transmit a much greater volume of information, necessitating a media with much higher bandwidth. Since twisted pair cannot support the higher signalling rates, there has been significant interest in a low cost fiber solution. This paper discusses the suitability of plastic optical fiber (POF) for use in local area networks. It outlines the cost and performance advantages offered by POF, discusses the inherent limitations of the medium, and defines an application space where POF is the optimal solution.
The local area network (LAN) market has been projected to maintain continued rapid growth throughout the 1990s. In addition, the volume and speed of data being transmitted over these networks is also expected to rise dramatically. These trends will necessitate the use of a medium capable of supporting that higher bandwidth, i.e., fiber optics. Glass fiber, the traditional networking solution has the disadvantage of high cost, both of components and installation. Consequently, this has discouraged widespread use. Plastic optical fiber (POF), on the other hand, has many of the same advantages as glass fiber (e.g., high bandwidth and no radiated emissions or susceptibility) while offering the additional advantage of low cost and ease of installation. This paper describes a connection system designed for use in plastic optical fiber LANs. It discusses the overall design philosophy, provides performance data, and highlights the ease of termination which this connection system permits.
A high-bandwidth graded-index (GI) polymer optical fiber (POF) was successfully obtained by a new random copolymerization technique. The bandwidth of the GI POF is about 1 GHz (DOT) km, which is 200 times larger than that of the conventional step-index (SI) POF. The total attenuation of the transmission is 150 - 200 dB/km at 652 nm wavelength and the tensile strength is about 1600 kg/cm2.
Optical time domain reflectometry (OTDR) measurements have been performed on polished polymethylmethacrylate (PMMA) plastic fiber splices. After the dominant splice reflection sources due to surface roughness, inexact index matching, and fiber core misalignment were eliminated, an intrinsic OTDR signature 3 - 8 dB above the Rayleigh backscatter floor remained with all tested fibers. This minimum splice reflectivity exhibits characteristics that are consistent with sub-surface polymer damage and can be used for detection of PMMA fiber splices.
We show an assembly of plastic optical fluorescent fibers made by Optectron. A large number of colors can be obtained by the introduction of appropriated additives into the core of the fiber. These fluorescent POF are able to transform an ambient light into another light at wavelengths of longer wavelengths. The nominal output intensity of fluorescent fiber increases when the ambient light is increased, so these fluorescent POF are very sensitive to light and can be used for the detection and command of light. After examining the optical properties of fluorescent fibers, we describe some examples of applications in various domains.
A new kind of sensor under development in order to detect high energy x or gamma rays is presented. It is based on an inorganic scintillator optically coupled to a ribbon of fluorescent optical fibers. The basic configuration is briefly described. Investigations of the principal properties of the fluorescent fibers used for the detector are then reported: the fiber attenuation, the influence of long term bending; the emission and excitation spectra; the radiation resistance tested by means of a 60Co source and an 18 MV linear accelerator, etc. A detailed characterization of these fibers has been realized and complete experimental results are presented.
Several chemical sensors have been developed using plastic optical fibers. Plastic optical fibers offer many advantages over glass fibers, such as high numerical aperture, low-cost, high flexibility, and ruggedness. The sensing segment is made of novel porous polymer fiber, combined with selective chemical indications systems. By careful selection of polymer systems and indicators, the chemical reagents can be covalently bonded to the porous plastic fiber. These sensors can be used to detect a variety of chemical species and to measure various chemical parameters, both in vapor and solution. They provide high sensitivity and stability. Sensor characteristics, including dynamic range, linearity, and response time, can be tailored to meet specific applications by altering the polymer composition and polymerization procedure. A low-cost, compact optoelectronic and data acquisition subsystem has been designed and constructed to interface with the sensor probe. This system employs two- wavelength, solid-state light sources, which allow the system to be calibrated on-line.
Refined specifications for plastic optical fibers (POFs) intended for use in a growing medical sensors market are proposed. A unique extrinsic sensor configuration, exclusively using a POF as the light carrier element, presents major advantages in clinical applications. Marketing projections for the medical sensors reveal a high demand for these types of optical fibers.
Polymethylmethacrylate (PMMA) plastic optical fiber (500 micrometers diameter, fluoropolymer cladding) has been spliced using a fused silica sleeve and a variety of solvent/PMMA solutions as adhesives. Mechanical splicing using index matching fluid has also been investigated. To ensure good bonding and minimize scattering, fiber ends are polished prior to application of adhesive. Using an LED ((lambda) max approximately 640 nm), losses are routinely less than 1.0 dB/splice, and some adhesive formulations have exhibited losses as low as 0.2 dB/splice. Five-meter fibers with as many as ten splices/fiber have been monitored over a period of several months. No fiber has exhibited an increase in optical loss with time.
Polymer waveguide technology was exploited to build a photonic switch with enormous bandwidth capabilities at extremely low cost per path. A 6 X 6 ferroelectric liquid crystal array was used as a switching element to block or transmit light signals between input and output fibers. Visible laser sources, plastic fibers, PIN detectors, and our proprietary polymeric mixing rod couplers were used to construct the switch. The polymeric fibers, couplers, and switching element allowed us to eliminate the need to time division multiplex photonic channels through the switch because the optical paths were no longer costly. This in turn eliminated the electronic buffering and synchronization requirements of the switch.
A novel plastic image-transmitting fiber (PIF) has been developed to meet the demand for improved optical fibers used in endoscopic applications. This fiber has a circular cross- sectional diameter of approximately 0.5 mm consisting of about 3,000 fiber elements corresponding to as many pixels when the image is represented using an appropriate display mechanism. The resolution, as measured by the USAF Test Target Method, is greater than 50 lp/mm. The flexural elastic modulus is 350 kg/mm2, less than one-tenth of the value for silica fibers. And, flexural endurance tests indicate that the minimum bending radius is 2 mm under repeated bending.
Regarding the section of plastic optical fibers (POF), the most common type is the circular section, of which the diameter varies from 0.1 mm to 5 mm. However, with our process of fabrication, we realize other shapes such as square, rectangular, and even hexagonal sections. POF with particular shapes in the transversal and longitudinal direction can be used to make anamorphosors, looked for in many applications.
The oldest application of Plastic Optical Fibers (POF) is without
doubt the transmission of light. ln the early 80's Dupont de
Neiiours made some findings which were the beginning of the
development of plastic optical fibers.
Ten years later, with the progress of technology, lighting with POF
stimulated the interest of many users, in particular architects and
In this paper we will describe several systems of illumination
developed by Optectron France using POF, from these installations we
have obtained technical Information which were unavailable until now,
and which will be applied in new and even more complex projects.
We describe the application of scintillating plastic optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described.