Polarization beam splitter based fiber-optic gyroscope operating in open-loop with extended dynamic range

We propose and demonstrate a novel fiber-optic gyroscope (FOG) in which a pair of polarization beam splitters (PBS) is used to route light to and from a Sagnac loop that senses rotation with significantly reduced optical loss. In addition, an orthogonal demodulation algorithm (ODA) is implemented using low-cost digital circuitry in an open-loop configuration to accurately extract the Sagnac phase shift with an extended dynamic range. With a 1km polarization maintaining coil, we achieved a bias instability and angle random walk of 0.0655 degrees /h and root 0.0059 degrees / h, respectively, with an extended measurement range of more than +/- 500 degrees /s and a scale factor nonlinearity of 743 ppm.