METHOD OF FABRICATING A CYLINDRICAL OPTICAL FIBER CONTAINING AN OPTICALLY ACTIVE FILM

摘要

A method of forming a preform which has a glass core (10) surrounded by an outer glass cladding (16) with a coating (18) of an optically active material disposed between the core (10) and cladding (16). The method includes providing a glass core (10) having a viscosity which lies within a given preselected temperature range, followed by forming a substantially homogeneous coating (18) of an optically active material over the surface of the core, with the coating having a viscosity which is equal to or less than the viscosity of the glass core. A glass cladding (16) is formed over the coated layer (18), with the cladding (16) having a viscosity which overlaps the viscosity of the core glass (10) and a thermal coefficent of expansion compatible with that of the core. The optically active material is an inorganic material which includes a metal, metal alloy, ferrite, magnetic material or a semiconductor. The invention includes the product formed by the process.