The level of drift produced by coherent backscatter in the optical fibre gyroscope is investigated. In particular the phase modulated minimum configuration system is considered and conclusions drawn concerning the optimum modulation frequency and the feasibility of incorporating a laser source in an inertial grade gyroscope. It is shown that the optimum modulation frequency is approximately one sixth of the eigenfrequency of the gyroscope and that at this point the backscatter is independent of the coupling ratio, environmental effects and rotation rate.
I. P. Giles,
"Coherence In Optical Fibre Gyroscopes", Proc. SPIE 0586, Fiber Optic Sensors I, (7 August 1986); doi: 10.1117/12.951158; https://doi.org/10.1117/12.951158