Tapered photonic crystal fiber couplers for optical integration

At the present paper the photonic crystal coupler of an optical fiber, which has been made by the adiabatic tapering of the optical fiber based on the photonic crystal is presented. In our investigation an effective refractive index model of two-dimensional photonic crystal was used. This model allows analyzing the waveguide structures, which work on the effective index waveguiding in a defect of the photonic crystal. The effective refractive indexes of such couplers were numerically found. Using this model the field distribution in these couplers were investigated and were calculated its losses. It was shown that the couplers with smaller input diameter and the fixed output diameter have smaller losses.