Fiber Optics
“Fiber-optic communicationis a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. First developed in the 1970s, fiber-optic communication systems have revolutionized the telecommunications industry and have played a major role in the advent of the Information Age. Because of its advantages over electrical transmission, optical fibers have largely replaced copper wire communications in core networks in the developed world.”
“An optical fiber consists of a core, cladding, and a buffer (a protective outer coating), in which the cladding guides the light along the core by using the method of total internal reflection. The core and the cladding (which has a lower-refractive-index) are usually made of high-quality silica glass, although they can both be made of plastic as well. Connecting two optical fibers is done by fusion splicing or mechanical splicing and requires special skills and interconnection technology due to the microscopic precision required to align the fiber cores”
(Wikipedia, Fiber Optics, 11,26/2010)
“Plastic optical fibers (POFs) are highly promising transmission media for future home networking.In comparison to glass optical fibers (GOFs), which are commonly used in core and metropolitan networks, POFs offer many advantages such as great flexibility and easy handling. This review begins with the basic concepts of optical fibers and moves on to the early history of loss reduction in POFs. What drastically changed the status of POFs in the communications field was a graded-index technology that improved the bandwidth to over 1 gigabits per second. However, even after the loss and bandwidth were enhanced to their limits, the performances of POFs were insufficient for market demand when using conventional optical polymer materials such as poly(methyl methacrylate). Recently, this problem has been solved by several lines of material research using fluorinated polymers. As a result, high-speed optical home networking by POFs has become more realistic.”
Koike and Koike, Keio University and Polytechnic Institute of New York University, 2010
Recent US Patents
10/12/2010
7,811,640
Methods for fabricating polymer optical waveguides on large area panels
Charters of PPO, Australia formedoptical waveguides based on a three layer structure comprising a lower cladding layer, a light guiding core layer and an upper cladding layer, supported on a substrate. (RDC 1/10/2011).
8/10/2010
7,771,794
Active energy ray-curable, organopolysiloxane resin composition, light-transmitting component, and method for manufacturing the light-transmitting component
Watanabe et al of Dow Corning Toray has developed a silicone fiber optics material consisting of silicone with epoxy and aromatic hydrocarbon groups with a photoinitiator. (RDC 10/13/2010)
Recent Journal Articles
2/4/2011
New Nonlinear Polyurethane: Synthesis and Optical Properties
(1606 – 1610) Polymer - Plastics Technology and Engineering 49 #15 (2010)
Issam and Sankar of the Universiti Sains Malaysia, Malaysia synthesized the compound 3,4-di-(2'-hydroxyethoxy)-4-diphenyl-hydrazonomethyl from the reaction of 3,4-dihydroxy-4-diphenyl-hydrazonomethyl with 2-chloro-1-ethanol in a 1:2 mole ratio, and subsequent reaction with methylene-4,4'-diphenyldiisocyanate (MDI) to produce the new nonlinear polyurethane. (RDC 1/3/2011)
Novel poly(3,4-dialkoxythiophene)s carrying 1,3,4-oxadiazolyl-biphenyl moieties: synthesis and nonlinear optical studies
(112–118)Polymer International 60 #1 (2011)
Hegde et al of the National Institute of Technology Karnataka and the Raman Research Institute, India synthesized two new donor–acceptor types of polymer, poly{2-(biphenyl-4-yl)-5-[3,4-dialkoxy-5-(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-1,3,4-oxadiazole}s starting from 2,2′-sulfanediyldiacetic acid and diethyl ethanedioate through multi-step reactions. The polymerization was carried out via the polyhydrazide precursor route. The polymers showed bluish-green fluorescence in solutions. The electrochemical band gaps of the polymers were determined to be 2.16 and 2.22 eV. The polymers showed strong optical limiting behaviour due to effective three-photon absorption. The values of the three-photon absorption coefficients for the polymers were found to be 9 × 10−24 and 17 × 10−24 m3 W−2, which are comparable to those of good optical limiting materials. (RDC 2/3/2011)
1/21/2011
Measurement and Analysis of the Angular Guided-Wave Depolarized Light Scattering Patterns from Block Copolymer Thin Films
(10071–10077) Macromolecules 43 #23 (2010)
Fang et al of Polytechnic Institute of NYU and University of California analyzedthe angular scattering patterns in guided-wave depolarized light scattering from 500 nm thick diblock copolymer thin films of poly(styrene-block-isoprene) using diffraction grating couplers.. Measured patterns are well fitted using a grain model consisting of disks lying in the film plane with elliptical cross sections, randomly oriented optic axes, and variable-length major axes. (RDC 1/18/2011)
10/29/2010
Frozen-in birefringence and anisotropic shrinkage in optical moldings: II. Comparison of simulations with experiments on light-guide plates
(5623-5639) Polymer 51 #23 (2010)
Isayev, Lin and Kwon of the University of Akron simulated thermally-induced birefringence by a combination of constrained and free cooling during molding and compared the results to polystyrene and two optical grade polycarbonates. . A good agreement between the simulated and measured anisotropic shrinkages in LGP moldings at various processing conditions was observed. (RDC 12/16/2010)
Review Articles
11/26/2010
Review
Progress in low-loss and high-bandwidth plastic optical fibers
(pages 2–17) Journal of Polymer Science B: Polymer Physics 49, #1 (2011)
Koike and Koike point out that polymer optical fibers (POFs) have long been overshadowed by the glass optical fibers (GOFs) that have connected the world. The performance and usage of POFs has gradually and steadily improved. POFs are no longer just alternatives to GOFs, given their clear advantages for short-range networks. (RDC 11/23/2010)