Residual intensity modulation-induced error in resonator fiber optic gyroscopes with triangular phase modulation.

Area of Science:

• Optical engineering
• Photonics
• Sensor technology

Background:

• Residual intensity modulation (RIM) is a key instability source in phase-modulated optical detection.
• In resonator fiber optic gyroscopes (RFOGs), RIM degrades bias stability by causing nonzero output signals at resonance.
• The precise origins of RIM remain incompletely understood.

Purpose of the Study:

• To experimentally investigate RIM in Y-branch waveguide modulators using triangular phase modulation.
• To develop a model for analyzing RIM-induced errors in RFOGs with triangular modulation.
• To identify methods for mitigating RIM-induced errors in RFOGs.

Main Methods:

• Experimental analysis of RIM in a Y-branch waveguide modulator subjected to triangular phase modulation.
• Development of a theoretical model to quantify RIM-induced errors in RFOGs.
• Experimental study of RIM's equivalent modulation depth with varying acquisition times and symmetrical acquisition strategies.

Main Results:

• A model was established to analyze RIM-induced errors in RFOGs under triangular phase modulation.
• Symmetrical acquisition within a triangular wave period was shown to reduce RIM-induced errors.
• Experimental results demonstrated that symmetrical acquisition can completely eliminate RIM-induced errors.

Conclusions:

• Symmetrical acquisition is an effective strategy to mitigate RIM-induced errors in RFOGs.
• Understanding and controlling RIM is crucial for improving RFOG bias stability.
• This study provides a practical method for enhancing the performance of optical gyroscopes.