Multi-Harmonic Modulation in a Fiber-Optic Gyroscope

• Main Authors: Kozuma, M. (Author), Miranda, M. (Author), Miyazawa, Y. (Author), Takei, N. (Author)
• Format: Article
• Language: English
• Published: MDPI 2023
• Subjects: A.Fibres; article; Bias modulation; fiber optics; Fiber optics; fiber-optic gyroscope; Fibers; Fibre optics gyroscopes; Gyroscopes; Harmonic analysis; Modulation methods; multiple harmonics; Multiple harmonics; noise; Phase noise; Phase-noise; random walk; Relative intensity noise; relative-intensity noise; signal noise ratio; Signal to noise ratio; sinusoidal bias modulation; Sinusoidal bias modulation; spike; Thermal phase; thermal-phase noise; Thermal-phase noise
• Online Access: View Fulltext in Publisher; View in Scopus
• ISBN: 14248220 (ISSN)
• DOI: 10.3390/s23094442

Optimizing the bias modulation of a fiber-optic gyroscope is crucial to improving its precision. In this study, we propose and demonstrate the use of multiple harmonics of sinusoidal modulation as an intermediate alternative to the widely used modulation methods: sinusoidal and square-wave modulation. We show that this alternative integrates the advantages of each modulation method by providing a smooth modulation that produces a clean, spike-free output and a satisfactory signal-to-noise ratio. By using three harmonics of modulation in combination with a high frequency to reduce thermal phase noise, we obtained an angular random walk of (Formula presented.) and a bias instability of (Formula presented.). This is the highest performance ever reported for fiber-optic gyroscopes. © 2023 by the authors.