Design of polarization-preserving photonic crystal fibres with elliptical pores

In this paper we discuss a microstructure of air capillaries with an elliptical cross section in a tread of glass, which gives an opportunity for the creation of a polarization-preserving fibre with very small beat length between the fundamental modes of different polarization. It is shown here that the fibre can be designed in such a way that only fundamental modes are guided. However, it is not possible with this process to create a photonic crystal fibre which can guide only one fundamental mode.