This example shows modeling of an Interferometric Fiber-Optic Gyroscope (I-FOG) in OptSim. The interferometric fiber-optic gyroscope (I-FOG) is today an important option for many civilian and military applications such as inertial navigation and guidance systems for automotive, aircraft, and space industries, satellite antennas pointing and tracking, mining and tunneling operations, and helicopter attitude control. It brings the advantages of solid-state technology (guided-wave optics and low-voltage low-power electronics) with a cost reduction that enlarges its domain of application.
The I-FOG is based on the Sagnac effect, which produces in a ring interferometer a phase difference proportional to the dot product of the rotation rate vector by the area vector enclosed by the optical path, and takes advantage of single-mode optical fiber as the propagation medium. Several critical system components and design characteristics affect the FOG performance: the coil optical fiber; the active source; the passive and integrated-optics components; the optical circuit configuration for reciprocity; and the detection schemes.
The figure below shows OptSim layout for the I-FOG: