Parabolic fiber cutoffs: A comparison of theories

Abstract
The numerical values of cutoff for parabolic core uniform cladding fibers as obtained from various theories are found to disagree. Only one numerical method and an analytical result presented here correspond. The cutoffs are found to be well ordered and with periodic gaps, a situation not found in step-index guides. Finally, simple formulas yield the cutoff values and the total number of propagating bound modes.