Propagation of Light in Photonic Crystal Fibre Devices
  We describe a semi-analytical approach for three-dimensional analysis of photonic crystal fibre devices. The approach relies on modal transmission-line theory. We offer two examples illustrating the utilization of this approach in photonic crystal fibres: the verification of the coupling action in a photonic crystal fibre coupler and the modal reflectivity in a photonic crystal fibre distributed Bragg reflector. 
Ali Dabirian, Mahmood Akbari, and Niels Asger Mortensen