Abstract: The present invention relates to an optical single-mode fiber having low dispersion for the wavelength division multiplex operation (WDM) of an optical transmission path, which is made of a central fiber core having the radius r1, two inner fiber cladding layers having the outer radius r2 and a, respectively, where a>r2, and an outer fiber cladding layer, the refractive index profile n(r) of the fiber not being constant as a function of the fiber radius r (triple-clad fiber). By properly selecting the profile form and the refractive index differences between the core layers and cladding layers, respectively, conventional fabrication methods can be used to manufacture a fiber having low dispersion within the wavelength range of about 1400 to 1700 nm and, thus, in the third optical window, fiber attenuation not being increased thereby.

Abstract: A method of manipulating a compensation fiber for compensating the high negative dispersion of a fiber laser in the second optical window. The active fiber of the fiber laser is linked to a compensation fiber which consists of a step-index quartz glass core with a sheathing. By doping the compensation fiber sheathing with fluorine in a targeted manner, a positive value is set for the dispersion of the compensation fiber. Subsequent dimensioning of the length of the compensation fiber increases the set dispersion value to the positive dispersion value necessary for complete compensation of the dispersion of the fiber laser.