Enhanced Sensitivity in Fiber Optic Gyroscopes Achieved Through Dual-Channel Improved Cooperative Modulation

Interferometric fiber optic gyroscopes (IFOGs) are essential in precision measurement applications such as inertial navigation and geophysical exploration. Increasing their sensitivity is critical for advancing precision measurement technologies and enabling sensor miniaturization. Relative intensity noise (RIN) is the primary factor limiting IFOG sensitivity. To address this challenge, we propose a dual-channel improved cooperative modulation scheme featuring a source-sharing configuration, and a novel improved demodulation technique is introduced, which significantly improves the signal-to-noise ratio (SNR) for angular velocity measurements. Compared with single-channel systems, dual-channel systems achieve significant performance enhancements. The self-noise level decreases from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.0} \times{10}^{-{6}} \ \text {rad/s/Hz}^{\text {1/2}}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${3.7} \times{10}^{-{8}} \ \text {rad/s/Hz}^{\text {1/2}}$ </tex-math></inline-formula>, a 27-fold improvement. Furthermore, the angular random walk (ARW) and bias instability (BI) improve by approximately 27 fold and 7 fold, reaching <disp-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">\begin{align*}{9.3} \times{10}^{-{5}} \ \text {$^{\circ }$/h}^{\text {1/2}}\end{align*} </tex-math></disp-formula> and <disp-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">\begin{align*}{5.0} \times{10}^{-{4}} \ \text {$^{\circ }$/h}\end{align*} </tex-math></disp-formula>, respectively. Experimental validation, including tests on scale factor nonlinearity and dynamic response, provides evidence of the system’s sensing capabilities. Through extensive experimental validation, the system exhibits exceptional performance, with promising implications for advancements in precision measurement.