초록 ▼

A single mode optical waveguide is fabricated in a manner such that the core thereof is subjected to a stress-induced birefringence. A hollow intermediate product is formed by depositing layers of cladding and core glass on the inner surface of a substrate tube. Opposite sides of the intermediate pr

A single mode optical waveguide is fabricated in a manner such that the core thereof is subjected to a stress-induced birefringence. A hollow intermediate product is formed by depositing layers of cladding and core glass on the inner surface of a substrate tube. Opposite sides of the intermediate product are heated to cause it to collapse into a solid preform foreproduct having an oblong cross-section. A layer of flame hydrolysis-produced soot having a circular outer surface is deposited on the preform foreproduct and is consolidated to form a dense glass cladding layer thereon. The TCE of the outer cladding layer is different from that of the preform foreproduct on which it is deposited so that when the resultant preform is drawn into a fiber, a stress-induced birefringence exists in the core.

대표청구항 ▼

A method of fabricating an optical waveguide fiber comprising the steps of providing a preform foreproduct having an oblong, centrally disposed glass core surrounded by a layer of inner cladding glass, the refractive index of said core glass being greater than that of said cladding glass, the cross-

A method of fabricating an optical waveguide fiber comprising the steps of providing a preform foreproduct having an oblong, centrally disposed glass core surrounded by a layer of inner cladding glass, the refractive index of said core glass being greater than that of said cladding glass, the cross-sectional shape of said foreproduct having two opposed rounded sides and two opposed flatter sides, depositing a layer of flame hydrolysis-produced soot in nonuniform thickness on the outer surface of said inner cladding layer, the thermal coefficient of expansion of said glass soot being different from that of said inner cladding layer by at least 1×10-7/°C., the thickness of said soot layer being greatest over the flatter sides of said preform foreproduct, heating the resultant article to consolidate said layer of glass soot, thereby forming a solid glass draw blank, and drawing said solid glass draw blank to form a polarization retaining single-mode optical waveguide fiber.