Propagation characteristics of coupled surface plasmon polaritons in PVDF slab waveguides at terahertz frequencies

We present the propagation characteristics of y-polarized coupled surface plasmon polariton (SPP) modes supported by ferroelectric polyvinylidene fluoride (PVDF) slab waveguides at terahertz (THz) frequencies. Employing a two-dimensional (2D) finite-element method, four y-polarized coupled SPP modes are obtained, where two modes exhibit long propagation lengths (∼700 μm) and the others provide subwavelength confinement. It is shown that PVDF is a promising material for plasmon-like excitation in the terahertz regime and results in strong confinement of THz wave propagation in SPP-based coupled waveguides.