In UK Patent 2012983 A, a method is described for obtaining optical glass fibers with a noncircular core based on the use of surface tension forces. The starting material is a twolayered glass blank with a circular core and a sheath whose outer boundary is also circular. Since the surface tension on the boundary between the sheath and the core is much less than the surface tension on the boundary of the blank, there will be a fairly long period during which the boundary of the blank is already almost circular, whereas the boundary between the sheath and the core is deformed as a result of the flow of material and is still far from circular. If during this period the blank is cooled, it will have a circular overall cross section and a noncircular core, whose shape will be more or less preserved when the blank is subsequently drawn into a fiber. In some cases the core is shaped directly during the drawing process. In this paper, to quantitatively describe this process, the problem is rigorously formulated within the framework of Stokes flow capillary hydrodynamics and treated within the limits of the linear approximation.
|Number of pages||7|
|Publication status||Published - 1988 May 1|
ASJC Scopus subject areas
- Fluid Flow and Transfer Processes