A Linear Birefringence Measurement Method for an Optical Fiber Current Sensor

Area of Science:

• Optics
• Fiber Optics
• Sensor Technology

Background:

• Optical Fiber Current Sensors (OFCS) are crucial for electrical measurements.
• Accurate birefringence measurement is essential for OFCS performance.
• Existing methods have limitations, particularly with large birefringence values.

Purpose of the Study:

• To propose and validate a novel linear birefringence measurement method for OFCS.
• To address the multi-valued problem in birefringence measurement.
• To eliminate the influence of azimuth angles in the measurement system.

Main Methods:

• Development of a specific optical configuration for birefringence measurement.
• Demonstration of a method to eliminate azimuth angle effects.
• Mathematical determination of the relationship between linear birefringence, Faraday rotation, and sensor output.
• Simulation and solution for multi-valued linear birefringence.
• Experimental validation using OFCS with varying fiber turns.

Main Results:

• The proposed method successfully measures linear birefringence in OFCS.
• Experimental results show accurate measurements for birefringence values up to 3.5198 rad.
• The method is effective across the full range of linear birefringence, unlike prior techniques.
• Elimination of azimuth angle effects was demonstrated.

Conclusions:

• The proposed linear birefringence measurement method is feasible and accurate for OFCS.
• This method overcomes the limitation of requiring birefringence to be less than π/2.
• The technique offers a robust solution for full-range birefringence measurement in optical sensing applications.