Propagation constant and waveguide dispersion of single-mode fibers measured from far-field

Wavelength-dependent measurements of the far-field pattern can be evaluated to yield a mode-field radius. It was recently proposed to fit these data to a formula that contained all the parameters necessary to construct an empirical relation for the wavelength dependence of the propagation constant. The authors report on the feasibility of this technique, using actual measurement data. They discuss the calculation of the waveguide dispersion from the measured mode-field radius. In both cases the choice of the empirical fitting function proves to be of great importance