Dispersion-compensating fiber

摘要

Disclosed is a dispersion-compensating (DC) optical fiber Ä10Ü that is designed to support only the fundamental mode of radiation at 1550 nm. The DC fiber is fabricated from silica glass and has a refractive index profile that includes a core region Ä51Ü surrounded by a cladding region Ä52Ü having a nominal refractive index n4. The core region includes a central core Ä511Ü having a nominal refractive index n1, a "trench" Ä512Ü surrounding the central core having a nominal refractive index n2, and a "ridge" Ä513Ü surrounding the trench having a nominal refractive index n3. A range of refractive index profiles has been found that provides figures of merit that are greater than 300 ps/(nm.dB) and relative dispersion slopes that are greater than 0.01 nm<-1>. The range is conveniently expressed in terms of index differences and radial dimensions: central core: radius = 1.5 +/- 0.5 mu m, and 0.015 < n1 - n4 < 0.035; trench: width = 3.5 +/- 1.0 mu m, and -0.012 < n2 - n4 < -0.006; and ridge: width = 2.0 +/- 1.0 mu m; and 0.002 < n3 - n4 < 0.015.