In this reported work, an excellent design model of quasi-shape of cladding areas with rotated-Hexa based elliptical shape of core areas in photonic crystal fiber (Q-PCF) has been reported for terahertz (THz) waves of communication signals. Here, we have presented a six-layer circular air hole in the quasi-shape of cladding regions with two layers rotated-Hexa-based ellipse shape of air holes in the core regions of photonic crystal fiber (Q-PCF) for analysis of communication networks in the terahertz (THz) regime. On the other hand, perfectly matched layers (PML) and finite element method (FEM) based on COMSOL software tool are used to design this photonic crystal fiber (Q-PCF). For short and wide-band of communication sectors, our proposed quasi shape-based photonic crystal fiber (Q-PCF) is highly useful because of reducing different types of losses such as ultra-low effective material loss (EML), confinement loss, and scattering loss in the terahertz (THz) regime. After analysis of numerical results, our suggested quasi shape-based photonic crystal fiber (Q-PCF) shows an ultra-low effective material loss (EML) of 0.0163 cm−1, power fraction in the core area and large effective area of 74%, 5.52 × 10−8 m2, confinement loss of 3.25 × 10−12 cm−1 and the scattering loss of 1.23 × 10−10, respectively at 1 terahertz (THz) frequency range. Moreover, our proposed quasi photonic crystal fiber (Q-PCF) discloses a single-mode propagation by the graphical results of V-parameter over 0.80–3 THz frequency range. As a result, we can say clearly that the reported Q-PCF fiber will be highly appropriate for terahertz (THz) wave propagation for many communication networks such as bio-medical signals and various data transfer communications system.
