Photonic crystal fibers (PCFs) are promising candidates for 5G communication systems, as they offer low loss and high bandwidth. In this paper, we use COMSOL Multiphysics software to design and optimize PCF structure suitable for optical fiber communication in the terahertz (THz) frequency range. The proposed model and simulation analysis based on light propagation, dispersion, and polarization effects in PCFs helps to explore how different parameters affects the performance . Hence, COMSOL simulation of the proposed model helps to design and meet the requirements of 5G networks and enables wireless communication.