Modern communications have reached unpredicted bit rates due to rapid and accelerating research carried out in the field of Photonics. A design and simulation of a polarization rotator using III-V materials (InP/InGaAsP) with a feasible fabrication process were performed. The polarization conversion efficiency of ~98% and polarization extinction ratio of ~17.3dB over 1530nm to 1570nm wavelength (C-band) was achieved. The study was used to select the etch stop layer, visualize the state of polarization at different lengths of the device, and predict the variability of the polarization rotator over different lengths. The selected device structure provides a significant fabrication tolerance enhancement factor which consists of a one-sided tapered ridge waveguide and a deeper-etch structure on the opposite side. This work offers a practical path toward the integration of a polarization rotator in a photonic integrated chip and would pave a way for future innovation.