Abstract:
Embodiments of the invention include a positive dispersion optical fiber (50, 55) that includes a doped core region (51, 56) with an index of refraction n 1 , a cladding region (54, 59) with an index of refraction n 2 , and first (52, 57) and second (53, 58) annular rings or regions therebetween with indices of refraction n 3 and n 4 , respectively. The various regions are manufactured in such a way that the refractive index value ranges are: 0.14 1 -n 2 )/n 2 3 -n 2 )/n 2 4 -n 2 )/n 2 2 -km) at a wavelength of 1550 nm. Also, the fibers have a relatively large effective core area, A eff , for example, greater than 100.0 µm 2 , and a relative dispersion slope (RDS) less than 0.0032 nm -1 . The mode field diameter (MFD) is at least 11.9 ± 0.7 µm. These desirable transmission characteristics are achieved without many of the manufacturing and economic limitations of conventional fibers.