This paper proposes the analysis of various parameters after simulations of Photonic crystal fibers having air holes arranged in octagonal shape. Some of the air-holes replaced by some other liquid of refractive index differ from air to achieve more effective responses. This Octagonal Photonic Crystal Fiber (O-PCF) consists of four rings in which the air holes are placed. Four holes in the innermost ring of O-PCF are filled with Ethanol instead of air. The parameter calculations are done by varying the hole diameters, pitch values, and wavelengths while keeping the perfectly matched layer (PML) values constant. COMSOL Multiphysics is the software platform used to design these proposed structures, which uses Finite Element Method (FEM). The calculation of confinement loss and graphical representation are done in MATLAB. The advantage of taking ethanol as a substitute of air is that the confinement loss is reduced as compared to the confinement loss with only air hole PCF structures.