This manuscript deals with a novel photonic crystal fiber (PCF) in which PCF's cladding region bears the air holes of square shape organized in a circular manner. The fiber core is perforated with four circular air-filled holes to instate high nonlinearity and large negative dispersion. The numerical analysis of the designed model is supported by the finite element method (FEM) based COMSOL Multiphysics tool. The optical properties of the propounded PCF like nonlinearity, dispersion, effective area and propagation loss have been observed by altering its geometrical dimensions, especially the diameter of four air holes introduced in the fiber core. Simulation outcome verifies a very high nonlinear coefficient value of 300 W− 1 Km− 1 which is the highest ever achieved value without using any nonlinear materials or liquids in the author's best knowledge. In parallel, the chromatic dispersion is also found negative and reached to the maximum value of -1689 ps/nm/km. Besides, the other essential optical parameters such as birefringence, numerical aperture, and propagation loss were also measured as 2.40×10− 3, 0.59, and 4.12×10− 11 dB/m along with an extremely high core power fraction of 99.98%. Hence, the propounded PCF is suitable for residual dispersion compensation, supercontinuum generation, solitons generation, polarization sustaining devices as well for high bitrate transmission.