Transmission loss and dispersion in plastic terahertz photonic band-gap fibers

We present an investigation into the transmission loss and dispersion of terahertz waves in plastic photonic band-gap fibers having a cladding with a finite number of air hole rings. The leakage loss and absorption loss caused by background material are analyzed by a full-vectorial two-dimensional finite difference frequency domain method and the lowest power transmission loss of 6.126 dB/m at 1.75 THz is realized. Numerical results show that a larger diameter-to-pitch ratio is suitable for lower transmission loss and lower group-velocity dispersion in plastic terahertz photonic band-gap fibers.