Phase-matching of the HE11 and HE13 modes of highly doped GeO2–SiO2 fiber waveguides at 1596 nm and 532 nm, respectively, for triple-photon generation

We theoretically investigate a phase-matching (PM) between the HE11 and HE13 modes at wavelengths 1596 and 532 nm, respectively, of a real germania-silica fiber waveguide, whose preform was made by MCVD technology. For several measured refractive index profiles of the fiber preform, the corresponding waveguide diameters, providing homogeneous PM, both with modal dispersion and power characteristics, are calculated. The PM parameters obtained for the real fiber are compared to that calculated for a standard step-index fiber model.