Narrow Results

This paper proposes a novel model to attain high birefringence and low loss in a slotted core-based photonic crystal fiber (PCF) structure in THz regime. The performance of the proposed PCF has been evaluated by applying finite element method (FEM) with full simulation software COMSOL Multiphysics V-5.1. The proposed model gains good optical properties such as high birefringence of 0.24, low effective material loss (EML) of 0.03 cm${}^{-1}$, low confinement loss of 6.5 × 10${}^{-13}$ (dB/m), low scattering loss of 2 × 10${}^{-3}$ (dB/m) and low bending loss of 7.4 × 10${}^{-20}$ (dB/cm). The proposed structure also exhibits the flattened dispersion for wider frequency response. However, the real-life fabrication of the suggested model is highly feasible using the current technology due to the unique shape of circular air holes in the cladding region. The outcomes make the proposed PCF a stronger candidate for polarization-preserving applications such as sensing, communications and filtering operations in THz band.

A triangle-platform-index core fiber is proposed, in which the refractive index distribution in the cross-section of the fiber core is composed of several closely connected triangles and a platform at the outermost layer. The simulation results show that the proposed fiber possesses an extremely large mode field area of $3110\mu {\mathrm{\text{m}}}^2$ at the wavelength of $1.06\mu \mathrm{\text{m}}$, and achieves single-mode operation state near a bend radius of 17 cm. Furthermore, several different mode field distributions, including Gauss-like distribution, flatten distribution and hollow distribution, are achieved. The proposed fiber can benefit suppressing nonlinear phenomenon to increase the output power level of fiber laser, and promoting special industrial processing.