Dispersion characteristics of bimodal heavy metal fluoride fibers at 1.3 mu m

The design of heavy metal fluoride fibers having segmented-core refractive index profiles and operating a bimodal regime, with small modal dispersion or good equalization, between the LP/sub 01/ and LP/sub 11/ modes in the 1.3- mu m wavelength region is discussed. The concept of effective cutoff of the LP/sub 02/ mode has been used in order to maximize the operating V value. A practical bimodal equalized design example which has negligible extrinsic losses is provided in which equalization between the modes is within +or-25 ps/km over a wavelength interval of 160 nm ( approximately 1.2-1.36 mu m). Hence, the predicted bandwidth of the bimodal fiber is high over a broad wavelength interval.<>