Higher-order mode investigations by intermodal interference in a dual-core photonic crystal fiber

Koys M., Bugar I., Lorenc D., Buczynski R., Pysz D., Uherek F.

Laser Physics

18(10), 2008, 1153–1158, 10.1134/S1054660X08100083

This article presents an investigation of the linear optical properties of a dual-core photonic crystal fiber with a square lattice made of a multicomponent glass in a second communication window. An experimental method based on intermodal interference was used to determine the effective refractive indices of higher-order modes, with knowledge of the fundamental mode dispersion. The effective refractive indices were also determined by an FDTD-based simulation and the obtained values provided a good agreement in comparison to the experimental results. The obtained results help to clarify the nonlinear spectral transformation processes observed in the same fiber at propagation in the higher-order modes.