Dispersion-compensating fiber having a high figure of merit

Abstract

Disclosed is a dispersion-compensating (DC) optical fiber 10 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 51 surrounded by a cladding region 52 having a nominal refractive index n4. The core region includes a central core 511 having a nominal refractive index n1, a “trench” 512 surrounding the central core having a nominal refractive index n2, and a “ridge” 513 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 μm, and 0.015<n1-n4<0.035; trench: width=3.5 1.0±μm, and −0.012<n2-n4<−0.006; and ridge: width=2.0±1.0 μm; and 0.002<n3-n4<0.015.

Dependencies are inferred from the claim text.