# Single Mode FiberΒΆ

In this tutorial project we compute the fundamental propagation mode of a cylindrical optical fiber with a doped silica core.

The core has a relative permittivity and a diameter . The cladding has a relative permittivity and a diameter . We assume that the tangential component of the magnetic field vanishes on the outer boundary. We want to find two eigenmodes near 1.5 which is our initial guess for the effective refractive index. A detailed description of the parameters needed for the input files is given in the basic example Propagating Mode.

The figure below shows the z-components of the electric fields for the two computed eigenmodes (logarithmic scale). Both belong to the same effective refractive index, which is twofold degenerate. The eigenvalues are stored in the file eigenvalues.jcm.

The tutorial example Bent Single Mode Fiber shows how to compute the fundamental propagation mode of this fiber when it is bent.