Transfer Matrix Method with Gouy Phase Shift correction applied to a High Numerical Aperture fiber-to-fiber optical coupling analysis

In this paper, we present the transmittance and reflectance study of the optical coupling between two High Numerical Aperture (HNA) fibers using a new model based on the Transfer Matrix Method (TMM). The TMM is corrected by the effects of the Gouy phase shift and the mode overlap is used in the material between the fibers to calculate the coupling loss. The coupling is also simulated using the Eigenmode Expansion (EME) method, and these numerical results are compared with experimental ones. The Gaussian beam nonparaxial field equations are used to evaluate the phase of the light in the coupling region and to obtain the effective refractive index of the wave between the fiber facets. Our TMM approach produced results close to experimental ones. Our model is, at least, two orders of magnitude faster than a commercial solver, and easy to coding; highlighting this approach’s importance as a transmittance/reflectance simulation tool.