Integral equation analysis for higher order modes and cutoff frequencies of arbitrary profiles

A semianalytical method of analysis for arbitrary weakly guiding circular and noncircular profiles, which has its fundamental basis in perturbation theory and incorporates Green´s function and integral equation techniques in a powerful method of analysis possessing extremely high accuracy, is extended to the analysis of higher order modes and cutoff frequencies of arbitrary weakly guiding circular and noncircular profiles. Its accuracy is demonstrated by its application to several weakly guiding profiles, for which the method is found to be extremely accurate (<10^-5%). Furthermore, additional simplifications to the semianalytical method of analysis are presented, which dramatically reduce the number of calculations required for solution