Design Evaluation of DBR Fiber Laser Sensor for Directional Lateral Force Monitoring

This letter reports an analysis of the potential of distributed Bragg reflector (DBR) fiber laser sensor designed to monitor the force orientation information, and with the birefringence characteristics of optical fiber, enabling the measurement of a directional lateral force applied to the fiber. In system design, to interrogate birefringence variation of the sensor according to the change of applied force angles, a reference lasing signal was employed following the results of an analysis using heterodyning theory. Agreement between theoretical and experimental results was obtained for a constant lateral force loading from different directions corresponding to the variation of sensitivity in beat signals. The design created in this letter is based on fundamental principles and generic, thus suitable for use with any DBR fiber laser structure for vector sensor applications.