Polymer optical fibers

The sensors are constructed from Plexiglass cubes that have been drilled to accommodate a 600 /im optical fiber, polymer, and to provide a pathway for the analyte (Figure 2). The physical dimensions of the sensor are 15 mm by 12 mm by 10 mm. The volumes of the polymer reservoir and the reaction chamber are 100 /il and 40 jil, respectively. The lyophilized immunoreagents are incorporated into EVA at 1.5% (dryweight) for fluorescein-labeled anti-IgG antibody (F-Ab) and 8.0% Texas Red-labeled IgG (TR-Ag). Pieces of the polymers are then packed in the polymer reservoirs. 

Tenon tube (LD. = 1/16", OJ). = 1/4 ) with tiny boles (0J5 0 J6 mm) Optical Fiber Polymer matrix Paranim... 

Koike, Y. and Koike, K. (2011) Progress in low-loss and high-bandwidth plastic optical fibers. /. Polym. Sci. B, 49 (1), 2-17. 

Koike, Y, High-bandwidth graded-index polymer optical fiber. Polymer, 32, 1737, 1991. 

Optics. Good optical properties and low thermal resistance make poly(methyl methacrylate) polymers well suited for use as plastic optical fibers. The manufacturing methods and optical properties of the fibers have been reviewed (124) (see Fiber optics). Methods for the preparation of Fresnel lenses and a Fresnel lens film have been reported (125,126). Compositions and methods for the industrial production of cast plastic eyeglass lenses are available (127). 

Most Kaminsky catalysts contain only one type of active center. They produce ethylene—a-olefin copolymers with uniform compositional distributions and quite narrow MWDs which, at their limit, can be characterized by M.Jratios of about 2.0 and MFR of about 15. These features of the catalysts determine their first appHcations in the specialty resin area, to be used in the synthesis of either uniformly branched VLDPE resins or completely amorphous PE plastomers. Kaminsky catalysts have been gradually replacing Ziegler catalysts in the manufacture of certain commodity LLDPE products. They also faciUtate the copolymerization of ethylene with cycHc dienes such as cyclopentene and norhornene (33,34). These copolymers are compositionaHy uniform and can be used as LLDPE resins with special properties. Ethylene—norhornene copolymers are resistant to chemicals and heat, have high glass transitions, and very high transparency which makes them suitable for polymer optical fibers (34). 

GTP is a safe operation. A runaway polymerization can be quickly quenched with a protonic solvent. Since the group transfer polymerization goes to completion, no unwanted toxic monomer remains the silicone group on the living end after hydroxylation is removed as inactive siloxane. The living polymer in GTP is costlier than traditional polymerization techniques because of the stringent reaction conditions and requirements for pure and dry monomers and solvents. It can be used in fabrication of silicon chips, coating of optical fibers, etc. 

Light wave technologies provide a number of special challenges for polymeric materials. Polymer fibers offer the best potential for optical communications in local area network (LAN) applications, because their large core size makes it relatively cheap to attach connectors to them. There is a need for polymer fibers that have low losses and that can transmit the bandwidths needed for LAN applications the aciylate and methacrylate polymers now under study have poor loss and bandwidth performance. Research on monomer purification, polymerization to precise molecular-size distributions, and weU-controlled drawing processes is relevant here. There is also a need for precision plastic molding processes for mass prodnction of optical fiber connectors and splice hardware. A tenfold reduction in the cost of fiber and related devices is necessaiy to make the utilization of optical fiber and related devices economical for local area networks and tlie telecommunications loop. 

Baldini F. and Bracci S., Polymers for optical fiber sensors, in Polymer Sensors and Actuators, Y. Osada, D. E. De Rossi (eds.), Springer Verlag 2000, 91. 

In order to act as a transducer optode must be attached to the optical fiber. Bulks (>1 mm) of sol-gel matrix can be easily glued to the fiber tip, especially, if the polymer fiber is used39. The smaller optodes can be attached to fiber end by dip-coating method or simply by direct painting of the fiber-tip with a liquid gel. 

Traditionally, UV curable polymers have been utilized as coatings for wood and vinyl floors, but their applications have increased dramatically over the last twenty years to encompass many diverse areas, including optical fiber coatings (7), adhesives (2), disc replications (3-5), and microelectronics (6). This widespread use of UV cross-linked systems is attributed to their rapid, energy efficient curing and their solvent free, one piece formulations. Typically, UV curable systems require only a small fraction of the power normally utilized in thermally cured systems and their solvent free nature offers an environmentally safer alternative. 

This chapter provides an overview of the basic principles and designs of such sensors. A chemical sensor to detect trace explosives and a broadband fiber optic electric-field sensor are presented as practical examples. The polymers used for the trace explosive sensor are unpoled and have chromophores randomly orientated in the polymer hosts. The electric field sensor uses a poled polymer with chromophores preferentially aligned through electrical poling, and the microring resonator is directly coupled to the core of optical fiber. 

Fig. 2.16 (a) A schematic drawing of polymer microring resonator couple to a side polished optical fiber, (b) A microscope image of the fabricated EO polymer electric field sensor, (c) SEM image of resonators fabricated on the polished flat of a free standing fiber. The scale bar in the picture represents 100 pm. Reprinted from Ref. 15 with permission. 2008 Institute of Electrical and Electronics Engineers... 

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