| 摘要 |
<p>A method of forming a preform which has a glass core (54) surrounded by an outer glass cladding (52) with a coating of a particulate optically active material (12) disposed between the core and cladding. The method includes providing a glass core having a viscosity which lies within a given preselected temperature range, followed by forming a coherent coating of an optically active particulate material (12) over the surface of the core, with the coating material (52) having a viscosity which is equal to or less than the viscosity of the glass core (54). A glass cladding (52) is formed over the coated layer, with the cladding glass (52) having a viscosity which overlaps the viscosity of the core glass (54). The optically active material is an inorganic material which includes a metal, metal alloy, ferrite, magnetic material and a semiconductor. The invention includes the product formed by the process.</p> |
