Polarization-maintaining and Polarization-filtering Negative Curvature Hollow Core Fiber in THz Regime

A novel polarization-maintaining and polarization-filtering negative curvature hollow core (NC-HC) fiber in the THz regime is proposed in this paper. Two different transmission bandwidths of 0.42 THz and 0.21 THz with losses lower than 9 dB/m are attained for y- and x-polarization, respectively. The first and second transmission windows have the lowest loss of 1.5 dB/m at the frequency of 1.16 THz and 1.14 THz, respectively. Besides that, the proposed fiber has the birefringence higher than 10 ^-4 in the entire operating range of frequencies. Furthermore, 0.22 THz and 0.11 THz filtering bandwidth are achieved for the attenuation of the x- and y-polarized mode, respectively. Moreover, the bending loss is as low as 11.69 dB/m for 15 cm bending radius. The results reveal the high potential of the proposed fiber for polarization-maintaining and polarization-filtering applications in the THz regime.