ISSN:0032-3888    

DOI:10.1002/pen.760291702

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThe selection of the coatings/polymers used to fabricate optical fibers has been shown to be very important in determining their optical, mechanical, and connectorization performance. Material properties such as refractive index, optical transmission, and thermal coefficient of linear expansion are critical for coatings functioning as cladding materials. Coating adhesion to the glass surface, water absorption and water vapor permeation, as well as the ability to passivate the glass surface, have strong affects on the strength and fatigue behavior of fibers. Hard, thin, adhesive primary coatings are beneficial in making connectorization easier and more reliable.Many of the preferred properties for the fiber coating are different from those preferred for electrical wire, not only because light must be transmitted rather than electricity, but also because of the brittle nature of the silica substrate and the coupling between physical displacements and light transmission within the guiding material (microbend effects).The selection of cable materials is quite similar to that employed in the electrical wire and cable field. Much more attention must be given to cable design than for the latter. Designs/applications requiring tight jacketed or filled cables put special constraints on the selection of materials for the optical cables, which are more restrictive than for electrical cables.

ISSN:0032-3888    

DOI:10.1002/pen.760291703

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractA method is presented to study the mechanical behavior of soft, UV curable coating material as a function of temperature of the prepolymer at cure. For such materials, the crosslink density (hence, equilibrium modulus) is found to decrease with increasing cure temperature. The three primary coatings are: a polyurethane acrylate with a nominal equilibrium tensile modulus of 200 psi, a polyurethane acrylate with a nominal equilibrium modulus of 1200 psi, and a non‐urethane acrylate with a nominal equilibrium tensile modulus of 60 ps

ISSN:0032-3888    

DOI:10.1002/pen.760291704

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThe strength of the bond between primary coating and glass for a dual coated lightguide may be judged by fixing the coating to a substrate and pulling the glass out. The values obtained from such measurements are shown to exhibit a temperature and rate dependence similar to the mechanical properties of the primary coating for a given coating system. Here we combined temperature and rate data for a universal description of the coating to glass adhesion for a dual coating system.

ISSN:0032-3888    

DOI:10.1002/pen.760291705

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractAn important function of an optical fiber coating is to prevent optical losses due to microbending induced by lateral forces on the fiber. To protect the fiber over a wide temperature range the modulus of the primary and the secondary coating should be low and high, respectively, and temperature independent. However, selecting the most appropriate organic coating materials introduces a new source of optical losses. Since the linear thermal expansion coefficients of silica and the organic coatings differ by about two orders of magnitude, thermal, fluctuations will cause axial stresses. Cooling may then induce bending or buckling of the glass fiber in the soft primary coating, resulting in increased transmission losses. This effect is especially pronounced when a high‐modulus secondary coating is selected with a glass transition temperature above 80°C. For this type of coating the difference in radial shrinkage between the buffer and the top coating during cooling from the curing temperature becomes important. The influence of primary coating thickness is discuss

ISSN:0032-3888    

DOI:10.1002/pen.760291706

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThe thermo‐oxidative aging of a polyether urethane lightguide primary coating has been studied in films and dual‐coated fibers, In films, oxygen absorption is correlated with changes in modulus, yellowness, glass transition temperature, and sample weight. Thermal aging of fibers shows similar trends with regards to coating weight loss and discoloration as those observed with films. In addition, the force to mechanically strip the fiber follows the same patterns of change as the modulus of aged films. For both films and fibers, the time for onset of property changes varies inversely with temperature and can be delayed by the incorporation of an antioxid

ISSN:0032-3888    

DOI:10.1002/pen.760291707

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractIt is important to prevent transmission loss increase of optical fiber cables during a fire and fire fighting. One of the main reasons for the loss increase in a fire is the expansion and shrinkage of polymers used in optical fiber cables. The authors have developed a fire resistant optical fiber cable by studying the behavior of coating materials and coated fibers at high temperature. Polymer types investigated are thermoplastics, engineering plastics, and UV cured plastics. The fire resistant optical fibers are coated with a polymer which rapidly produces a carbonized layer by exposure to heat. The rapid carbonizing has the effect of reducing expansion and shrinkage. Besides the coating, the coated fiber is surrounded by carbon yarn to prevent breakage of the fiber. The fire resistant optical fiber cable passed the fire test at 840°C for 30 minutes and VTFT specified IEEE 383, without any breakage of the fibers. The optical loss of the fibers scarcely changed during the tests and after the tests. This paper presents the studies of coating materials and coated fibers at high temperature, the structure and properties of the coated fiber and characteristics of the fire resistant optical fiber cable

ISSN:0032-3888    

DOI:10.1002/pen.760291708

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractYoung's Modulus and the thermal expansion coefficient are material parameters used to predict the low temperature contraction of a fiber optic cable. In the past, room temperature values for these properties were used to estimate this contraction. In this paper, these properties have been determined as functions of temperature. Using these properties, the overall expansion coefficient of the cable was determined as a function of temperature. This overall coefficient was integrated from room temperature to the low operating temperature of the cable to predict the contraction of the cable. In this way, the temperature variations in the materials properties were incorporated into the design, resulting in a more accurate determination of the low temperature contraction of fiber optic cable.

ISSN:0032-3888    

DOI:10.1002/pen.760291709

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractTwo types of precisely molded fiber optic connectors have been developed. They are a cylindrical ferrule connector for a single fiber and a five‐fiber array connector for a tape fiber. The connectors are made by using a transfer molding technique with a silica‐filled thermosetting epoxy resin. The resin has low pressure and high melt‐flow characteristics, high dimensional accuracy, and high stability. The single fiber connector consists of a pair of plastic molded ferrules, a slitted alignment sleeve, and a plate spring. A fiber is inserted into a ferrule capillary and is fixed with adhesive. Then the fiber end face positioned in the center of the ferrule is polished to have a mirror surface. The five‐fiber connector consists of a couple of precisely molded ferrules, two alignment pins, and a plate spring. The five‐fiber ribbon is inserted into fiber receiving capillaries, of the ferrule, and fixed with adhesive. The fiber end faces on the ferrule mating face are polished to have a mirror face. In order to realize a low‐loss connection, the alignment pin holes and five‐fiber positioning capillaries on the ferrule mating face must be molded precisely. Various kinds of reliability tests on the connectors were conducted. All the results obtained proved that the connectors have entirely satisfactory properties for practical use. The connectors are now widely used in an optical fiber subsc

ISSN:0032-3888    

DOI:10.1002/pen.760291710

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThree potential applications for the “ladder” siloxanes in photonic technologies are discussed. These are: (1) as a silica fiber cladding material for which a silica fiber core‐siloxane cladding index depression (Δn) of 0.04 is observed; (2) as a fiber coating material to provide mechanical and environmental protection for which a siloxane coated silica core fiber is observed to have improved properties over a fiber coated with an epoxy‐acrylate or linear siloxane. Thus, the ladder siloxane can serve a dual coating/cladding function; and (3) as the passive lightguiding element in planar optoelectronics for which the index depression (Δn), as compared to silica, is 0.04 for the cured siloxane. 0.02 for a fenestrated silica obtained by removing the organic component from the siloxane, or values between 0.02 and 0.0 obtained by sintering this fenestrat

ISSN:0032-3888    

DOI:10.1002/pen.760291711

出版商:Society of Plastics Engineers    

年代:1989

数据来源: WILEY