Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education of China, Fujian Provincial Key Laboratory of Photonic Technology, Institute of Laser and Optoelectronics Technology, Fujian Normal University, Fuzhou 350007
The diffractive beam parameters of LP01 mode of fiber are analyzed in detail. Based on solving linear equations, two formulas for two kinds of mode-field radii as functions of normalized frequency are presented, and relations between angular radius of far-field divergence, beam propagation factor, and normalized frequency are given. Numerical calculation indicates that the maximal relative error is smaller than 1% within a reasonable parameter range.