摘要 |
A method of forming an optical waveguide by forming a first layer of glass having a predetermined refractive index on the outside peripheral wall surface of a substantially cylindrical mandrel. Thereafter, a second layer of glass is applied to the surface of the first layer, the second layer having a refractive index less than that of the first layer. The mandrel is removed from the assembly and the resultant cylindrical, hollow assembly is heated and drawn to reduce the cross-sectional area thereof, thereby forming an intermediate fiber. At least a portion of the intermediate fiber is disposed within a hollow glass cylinder having a refractive index similar to that of the second layer of glass of the intermediate fiber. The resultant composite structure is heated and drawn to reduce the cross-sectional area thereof and to collapse the inner, first layer of glass and to cause the inner surface of the glass tube to collapse upon the outer surface of the intermediate fiber to form a fiber having a solid cross-sectional area. |