The power transmitted by surface waveguide modes propagating along a semi-infinite dielectric fiber is determined. For a plane wave normally incident on the end of a perfectly circular fiber only the HE1m modes are excited. Of these modes the majority of the power is contained in the HE11 mode. Far above the cutoff conditions for the HE13 mode, approximately 99.8% of the incident power is contained in the HE11, HE12, and HE13 modes.
A. W. SNYDER, "Surface Waveguide Modes Along a Semi-Infinite Dielectric Fiber Excited by a Plane Wave," J. Opt. Soc. Am. 56, 601-605 (1966)