| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a negative dispersion optical fiber, etc., which has not only small wavelength dispersion but also a small dispersion slope (negative and large in absolute value) in a signal light wavelength band. SOLUTION: The negative dispersion optical fiber has negative wavelength dispersion and a negative dispersion slope at some wavelength in the wavelength band of 1.52 to 1.62μm. This negative dispersion optical fiber has at least a center core region which has an external diameter 2a and a maximum refractive index value n1, a 1st clad region which surrounds the center core region and has an external diameter 2b and a minimum refractive index value n2, a 2nd clad region which surrounds the 1st clad region and has a external diameter 2c and a minimum refractive index value n3, and an external clad region which surrounds the 2nd clad area, has an external diameter 2d (normally 125μm) and a refractive index n0 in the order from the center of the optical axis. The refractive indexes of the respective areas has a relation n2<n3<n0<n1.</p> |
