Group birefringence cancellation in highly birefringent photonic crystal fibre at telecommunication wavelengths

The spectral dependence of the group modal birefringence in a highly birefringent nonlinear photonic crystal fibre is studied both numerically and experimentally. The sign inversion and the cancellation of the group modal birefringence in the telecommunication window is demonstrated. Two simple experimental techniques are used to evaluate the wavelength of zero polarisation mode dispersion. The experimental results are in excellent agreement with numerical calculations based on vectorial beam propagation method simulations.