Proceedings Article | 4 January 2008
Proc. SPIE. 6837, Information Optics and Photonics Technologies II
KEYWORDS: Mathematical modeling, Optical fibers, Refractive index, Cladding, Error analysis, Laser applications, Single mode fibers, Solids, Beam propagation method, Radio propagation
A new method that the equivalent mode field radius can be acquired according to the equivalent matching efficiency
method is presented and the equation of the equivalent mode field radius, which is based on the core layer radius, the
normalized standing wave parameter and the normalized evanescent wave parameter, is given. Moreover, adopted
computer numerical simulation, a mathematical modeling between the equivalent mode field radius and the normalized
frequency of fiber is established. Based on this, the equation between the equivalent mode field radius and the
normalized frequency is introduced by curve fitting method. The numerical calculation indicates that it has a higher
precision. As for weakly guiding optical fiber, referred to the characteristic of the beam propagation factor of diffractive
beam of LP<sub>01</sub> mode from its end surface, it was illuminated that the Gaussian approximation for the mode field
distribution of LP<sub>01</sub> mode is rational. The characteristic of the field of the Gaussian approximation, which is based on the
equivalent mode field radius, is analyzed. The difference between the eigen mode field of LP<sub>01</sub> mode and the field of its
Gaussian approximation is discussed. From that, we can draw the conclusion that it is relatively accurate to adopt the
equivalent matching efficiency method to obtain the equivalent mode field radius.
