Reduction of dipersion in three-layer fiber waveguides

An analysis is made of some of the methods for reducing disperison in three-layer optical fiber waveguides with a step-like distribution of the refractive index. In particular, a calculation is made of the fiber parameters which ensure that the four lowest modes have the same group velocities. The results are given of a calculation of the material and waveguide dispersions in one-mode two- and three-layer waveguides. It is shown that the material and waveguide dispersions can be mutually compensated in a wide range of wavelengths $(\lambda=0,6-2,5\mu m)$ and normalized waveguide frequencies $(V=1-6)$.