A ferroelectric polyvinylidene fluoride-coated porous fiber based surface-plasmon-resonance-like gas sensor in the terahertz region

In this paper, a ferroelectric polyvinylidene fluoride (PVDF)-coated porous polymer fiber based surface plasmon resonance (SPR)-like gas sensor is proposed theoretically in the terahertz (THz) region based on the total internal reflection (TIR). In such a sensor, the phase matching is achieved by changing the fiber parameters and the plasmon-like phenomenon at the interface between the ferroelectric polyvinylidene fluoride (PVDF) layer and the gaseous analyte is discussed. Using a fullvector finite-element method, the core-mode loss of the fiber is calculated to measure the resolution of the sensor. The amplitude resolution is demonstrated to be as low as 1.45 × 10⁻⁴ RIU, and the spectral resolution is 1.30 × 10⁻⁴ RIU in THz region, where RIU means the refractive index unit.