On the mode field diameter of microstructured optical fibers

Mode field diameter (MFD) is one of the important parameters for determining the optical performance of single mode microstructured optical fibers (MOFs). We use our earlier-developed analytical field model for the mode of MOFs to obtain the mode field diameters (MFDs) using a variety of definitions in use. We also give analytical expressions for various MFDs. We further show that Gaussian approximation based analysis for the MFDs does not give satisfactory results. The processing of experimental data should not be based on the assumption of Gaussian field. It is suggested that MFD should be obtained by a processing of 2-dimensional field data, as a linear scan in one direction could give unsatisfactory results.