The asymmetric coupler based on the dual-core PCF

A novel asymmetric dual-core PCF coupler with wavelength-flattened response is proposed and its coupling characteristics of this coupler are investigated using full-vector finite element method and beam propagation method. Numerical simulation result shows that the wavelength-flattened response range as wider as hundreds of nanometer and the coupling length can be reduced down to the level of micrometer. The coupling properties can be tunable by changing the size of central air hole of the PCF coupler. In addition, the polarized-mode coupling shows that the proposed asymmetric dual-core PCF coupler is insensitive to the polarized mode.