Currently, Fiber-Optic Gyroscopes (FOGs) stand as a significant leap in inertial navigation sensor technology within the field of automation, control and navigation. There has been a recent global emphasis on exploring and enhancing high-precision Inertial Navigation Systems (INS), focusing on the pivotal role of fiber optic gyros as a fundamental sensor. FOGs are leading in many aspects over the mechanical gyros which were used before in earlier decades as they are lighter in weight, require no moving parts in operation, with higher sensitivity, and quicker in both start-up and warm-up procedures. In our present work we will investigate the performance of FOG under a distinct operational condition—namely, Near-Zero Rotation Rate for both basic and phase modulation configurations. We will use OptiSystem software package to simulate both configurations and show the initial challenges encountered during the simulation and detailed how subsequent phases effectively addressed these issues and pointing out the significant conclusion.