SNR enhancement of intensity noise-limited FOGs

The signal-to-noise ratio (SNR) of fiber-optic gyroscopes (FOGs) is directly impacted by the optical power coupled to the interferometric circuit. The optical intensity noise produced by the optical broadband source becomes the major component of the total noise at the output when the optical power reaching the detector is more than a few tens of microwatts. This work shows the implementation of a signal processing scheme capable of promoting reduction of the source intensity noise around the proper frequency of birefringent FOG, where the optimum signal demodulation takes place, yielding a better SNR. The total SNR has been enhanced 6.6 dB by means of a 20.4 dB reduction in the noise component associated only with the source intensity noise.