Research Of Signal Interrogation Technology Based On Dual-polarization Fiber Laser Sensors

With the rapid development of the sensing technique, and the updating necessary of the requirements for environmental monitoring, structural healthy monitoring and medical diagnose, which made the sensing devices more developed. Modern sensor technology is to warding to compact size, integrated and immunity to electronic. Fiber optical sensors as one of the most important sensors has been came into our vision, and applied in civil and military fields greatly, due to their advantage such as immune to electromagnetic, lightweight and easily multiplexing.However, among the various optical sensing techniques, the polarization heterodyne-based fiber sensors are externally exceptional due to stable output energy and higher solution, thus effectively complete conversion of the optical signal to an electrical signal and reaching the sensing goal. Additionally, different from traditional polarization heterodyne sensing field, an external force parameter with special loading orientation exists as a blind area; multi-parameter applied on the sensing fiber will introduce cross-sensitivity issues simultaneously.The paper is based on the existing problems, providing a novel fiber laser polarization heterodyne sensing technology to break through the difficulties. Based on the developing theory research, by inducing a light beam from DFB narrow-line width laser to beat signals with dual-frequency polarization so that they can generate three strong beat frequency signals, extracting the strength and orientation by analysising signal.Through theoretical analysis and experimental operation, we have achieved the external force loading angle measurement and the effective separation of multi-parameter. The proposed DBR fiber laser sensor shows a well recognition ability to force angle and multi-parameter parameter identification.