Terahertz photonic crystal fibers are analyzed and designed using a full-vectorial 2D finite difference frequency domain method with nonsplit-field anisotropic perfectly matched layers absorbing boundary conditions. By analyzing the effective mode areas of fundamental mode and second-order mode, a phase diagram which describes the regions of single-mode and multimode operation as well as the non-confined fundamental mode regime is obtained in the terahertz region. The single-mode terahertz photonic crystal fibers with near-zero flattened dispersion are designed based on this method by optimizing the structure parameters.
- Finite difference frequency domain
- Group-velocity dispersion
- Mode cutoff
- Terahertz photonic crystal fiber