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Author Chen, Chunming
Title Transport processes in drawing of optical fibers with core-cladding structure
Descript 138 p
Note Source: Dissertation Abstracts International, Volume: 68-02, Section: B, page: 1246
Adviser: Yogesh Jaluria
Thesis (Ph.D.)--Rutgers The State University of New Jersey - New Brunswick, 2007
For the purposes of telecommunications, optical fibers consist of a higher refractive index core and a lower refractive index cladding, which are drawn from a double-layer cylindrical preform. In this study, the thermal transport during the double-layer optical fiber drawing process has been numerically investigated
The radiation heat transfer in double-layer glass preform was calculated by using the zonal method. A parallel computational scheme was employed to determine the direct exchange areas. Three-band models were developed to represent the absorption coefficients of pure silica, GeO2-doped silica, and B2O3-doped silica. The radiative heat flux at the inner and outer interfaces of the preform, with a prescribed neck-down profile, and temperature distributions in the preform were obtained. The effects of different dopants and various process variables on radiation heat transfer were studied
The conjugate thermal and momentum transport in the core, the cladding, and the gas was then considered in detail. An iterative correction scheme was employed to generate the interfaces of the preform/fiber using radial velocity lumping. The numerical model was validated by comparing with the results from single-layer optical fiber drawing. The effects of changes in refractive index and absorption coefficients on double-layer optical fiber drawing were investigated. Variation in other physical variables particularly drawing speed and furnace temperature, were also considered
Finally, three widely used dopants, namely GeO 2, B2O3 and F, were considered. Physical properties of silica doped with these dopants were adapted from data in available literature. The draw tension and concentration of draw induced E' defects were calculated for optical fibers with different combinations of pure and doped silica regions. The effect of dopants on optical fiber drawing was studied in detail
School code: 0190
DDC
Host Item Dissertation Abstracts International 68-02B
Subject Engineering, Mechanical
0548
Alt Author Rutgers The State University of New Jersey - New Brunswick
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