Efficient Modulation and Processing Method for Closed-Loop Fiber Optic Gyroscope with Piezoelectric Modulator

Area of Science:

• Photonics and Optical Engineering
• Inertial Navigation Systems

Background:

• Interferometric fiber-optic gyroscopes (I-FOGs) offer linearized output and stability.
• Closed-loop compensation in I-FOGs typically requires electro-optic modulators and ramp modulation.
• All-fiber I-FOGs with piezoelectric modulators are usually open-loop, limiting performance.

Purpose of the Study:

• To present a novel, simple method for closed-loop Sagnac phase shift compensation in I-FOGs using piezoelectric modulators.
• To combine the benefits of closed-loop operation with the cost-effectiveness of all-fiber piezoelectric I-FOGs.
• To enable performance improvements in I-FOGs without custom components.

Main Methods:

• Implemented closed-loop compensation by adding sinusoidal modulation to the biasing modulation in an all-fiber I-FOG.
• Utilized a piezoelectric modulator for Sagnac phase shift compensation at sampling instants.
• Experimentally compared the proposed closed-loop method with traditional open-loop operation.

Main Results:

• The proposed method successfully achieves closed-loop compensation for the Sagnac phase shift.
• Experimental results demonstrate comparable performance to closed-loop systems but with piezoelectric modulators.
• The approach offers a cost-efficient performance enhancement over open-loop piezoelectric I-FOGs.

Conclusions:

• The developed method provides a practical and cost-effective way to achieve closed-loop compensation in piezoelectric I-FOGs.
• This technique merges the advantages of closed-loop stability with the simplicity and lower cost of all-fiber systems.
• The study validates a new approach for improving I-FOG performance using readily available components.